1. White only because yellow is god awful. There is the rare occasion where white doesn't show up well, but it's still more aesthetically pleasing than yellow.
2. I like something not too thick but not too thin either. More closer to thin than thick. As for styling, I'm fine with Black and tints. I used to think color-coordinated subs were cool once, but then I realized that they were just overkill. Two colors two differentiate when two people are talking at the same time should be the modern day limit.
3. I prefer reading minimalistic, sans serif fonts.
Pretentious fonts like old script are just no. Save that stuff for karaoke if you're going to use it.
4. I have no favorites really.
5. Direct translation of verbal tics. It's fine if they have some kind of relevance to the character's speech,
on the contrary. Otherwise, I prefer to have the verbal tic ignored in subs, left as is, or incorporated into their general speech pattern.
For example, there are two ways I have seen "de gozaru" handled. One was in Rumbel's Gintama where the subs just added "I daresay" to the end of everything. Nutbladder's Arakawa Under the Bridge translations, on the other hand, incorporated "de gozaru" into a old fashioned tone of speaking so that it read like Middle English.
Another example would be Marisa's "ze", where a boyish tone of speaking would be preferable over constant use of "yo".
6. The only standard for my subs are their ratings on MAL and their availability on bakabt.
7. -san, -chan, -kun, and -senpai are all fine to leave alone, since natural sounding English doesn't usually incorporate constant use of "Mr." or "Senior". Additionally, it's fine to leave them out as well.
-sama is kind of a gray area. I'm used to seeing it in subs, but I'm not averse to things like "lord" or "master".
-sensei I like to see translated if it is referring to modern profession. Teachers, doctors, writers, those kind of things I like to see "Mr. or Dr." in behind. When used as a standalone, I like to see it translated as teacher, doctor, etc.
The major exceptions to -sensei would be if it is used out of respect or a traditional profession such as martial arts instruction.