Okonoyamiyaki

Hmmmmmm I'm not too fussed about cleaning as long as it's not specifically bad. Like I don't mind it when sound effects aren't done (although I tend to translate them all when I do my own translations.) 
When it comes to outside bubble-text (non sound effects) it's best if it can look as close to the original as possible. That's hard on the redrawers, but otherwise it can end up being kind of distracting and when it's like a pivotal plot moment that can ruin the atmosphere. If redrawing is hanging up a release for weeks though, it doesn't need to be the most perfect ever. In the end, this is fan work and I don't think anyone would get really upset about it.

Watermarks I'm not too sure about, but if they're in the way, yeah.

Ah, along these lines though, I do have preferences for typesetting. I cannot stand vertical typesetting in English, it's almost impossible to read. Like, if it's absolutely necessary, turn it sideways (like you'd see on the spine of a book or movie) if you must. Otherwise just keep make it as thin as possible. Reading vertically in English is the biggest pain the the ass.
This mostly happens to like, battle cries and names of special moves but UGH.

Also gratuitous splicing of words, like when it doesn't fit and the typesetter does something like:
"I'm go-
ing to
save
the wor-
ld !!!"

No. Pick a smaller font or break it up better. D8

"I'm
going
to save
the
world
!!!"

Is just fine.

There is no excuse for that. Super gets in the way when reading. Like, it's unavoidable sometimes for legitimately long words but about 90% of the time it can be fixed if the perimeters are changed a bit.
Also not huge on lots of different font changes based on a typesetter's interpretation of the script when there wasn't a change in the original. Like, "I feel this person is probably speaking softly so I'll go with a curly font" is kind of forcing their interpretation on the reader. If it's something that's chosen to reflect the original manga's font change, it's awesome but I've seen a few where it was sort of more artistic interpretation. As it is, we already have the manga painted over slightly with the translator's brush no matter how objective we try to stay.

For me it would depend on the series. I'm a fan of marathoning (I'll often even go back and read a favorite series all at once,) but if it's a series that's currently being serialized in a magazine, I'd prefer not to wait if I don't have to. Like having to wait for monthly titles already can be painful.
Weeklies I wouldn't mind saving 1 to 3 of at once because like, honestly they're already really short releases and by the time I get into it, it's over.

For older things that are being scanslated with the tankouban though, bulk...ier releases (a couple chapters) is kind of nice. I agree that more than a few chapters  at once though can be kind of daunting and may mean that it gets moved to a backburner. Like more than 4 or 5 at once is like, "Oh I guess I'll do this after I read the shorter releases..."
I follow several...Uh... Hundred (?Too Many. Not Sure) current series so even if I read everyday, huge bulk releases might mean I get distracted or wander away in the middle.
I kind of like the idea of 2-3 chapters the most. Enough to get into it and excited but not so many I'm like "Gyaugh I have other things to read."

Either way as long as it doesn't just sit there for more than a few months without updates, I'm pretty happy. After 4 or 5 months, I end up not really being able to remember what was going on so even if there's a bulk release of like, a zillion chapters, it's a pain since I'll have to go back and remind myself. That's kind of demotivational at that point.

As far as text goes, I read both really long-winded wordy ones and really simple mostly fighting grunty ones. If it's interesting it doesn't really matter. For the ones without much text though, because they go so fast, I find one chapter releases kind of underwhelming and forgettable. I've found I'll often have to re-read a past chapter for context - especially the weekly JUMP type series. Contrarily, if it's a really wordy one and there's a huge bulk release, it might be harder to get through it in one sitting so it might sit on a side tab for a few weeks. 
 

Hmmm.... This kinda sounds like it could be Arata Kangatari? Also maybe not though. >< I don't think anyone other than the Aratas went over to the other worlds....
http://vatoto.com/comic/_/comics/arata-kangatari-r1790
I hope this helps!
Body switching/parallel universe manga are everywhere so it could be a lot of things....

It's not a recent boom or anything and I don't know how much of a thing this is in the West, but the number one trend I can't really wrap my head around? Religious, daily use of circle lenses. Especially in the industry I work in, it's like 80% or more of my peers use them and it's getting a bit terrifying to be looked at through enormous, vaguely brownish/grey tinted circle lenses framed by bloodshot eyes that haven't seen enough oxygen in years.

Specifically the really large circle lenses or daily, religious use of colored contacts. There's something about regularly or permanently modifying your iris size/color that seems off... Like, an innate self confidence issue. Not being able to face people without changing the color or size of the organ you use to see the world with seems inherently shady. Maybe I'm an old person but the whole "eyes are the window to the soul" thing rings out pretty true at times and I find it really hard to fully trust people that wear those like it's face underwear and not an optional statement accessory or impact piece - particularly at an age or station in life where you're no longer experimenting with fashion (using different colors and swapping them out for certain outfits or even infrequent use is cool) or identity searching, even just if trying to impress people at school or a special event.

I think it's super fine for cosplay too, as you're playing a character and therefore that type of modification makes sense (you're becoming them so it's cool to be viewing the world through "their" eyes) or even just casually here and there to go with particular outfits or for special occasions, but I've found that people that do it on a daily basis - to the point I have several acquaintances I literally don't know the real eye color of - is a bit unnerving.
There's never been a time aside from cosplay I've seen colored contacts or circle lenses and gone "That looks natural/better than your actual eyes. That really completes the look." If anything I tend to find it distracting ...Although I wonder if that's the point? They're there to draw attention away or to direct the attention to something that's controlled.

This is really the only thing like this I can think of. Like makeup and hair or whatever can drastically change a person's atmosphere (that's pretty cool) but constant, obsessive iris modification is the only one that squicks me out to that degree. Men and women.
Glasses (oh wait, but not colored lenses in glasses. That's also shady) and regular contacts are super fine though and yes, this is incredibly flawed logic, I know. I'm from the showa era and we're old like that XD
Just my feels. I know a lot of people like them.