Nothing wrong with characters that have solid eyes with no visible pupil. It can convey something different - red eyes scream evil, white eyes for a divine one, etc. I agree that if someone adds pupils against your wishes, you have a right to ask them to change that.
I like simple. Remember that reference sheets were heavily based on an animator's character sheet, and exciting poses and lots of text may look cool but ultimately ruin the purpose of the sheet itself (which exists to function less as a pretty art piece and more to help future commission artists...
NEVER meet them in person without talking to them for a while. NEVER meet them in a private place the first few times. Choose well-populated, well-lit, relatively intimate (as in not gigantic and overly crowded) places with easily observed enterances/exits like Starbucks or Panera Bread. NEVER...
I have quite a few anthro characters who have their own distinct personalities and settings for RP, but are just more characters than anything. I tend to make up and design characters, give them personalities, then promptly set them aside to rot. :v
There's no reason you can't also be an "albino" of some species of bird if you like the shape but not its natural plumage. Like a white eagle or hawk.
Ospreys, sea eagles, and swallowtail kites are 3 white birds of prey but they all have some black in them too.
I've made my fursona(s) almost every species under the sun but, like me, they are ALWAYS female. I just can't imagine being in the opposite gender's head well enough to make a convincing character. Even playing male characters in video games feels "off" and weird to me.
It depends on the character. The one with the most developed one is Aulendra (western dragon anthro). She lives in a world where dragon colors are based on royalty and stuff, sort of like Dragonriders of Pern meets DnD dragons. Most of the others either have no defined world or exist to RP in...
I have so many. A few are RP characters and some others just exist to give me a new OOC fursona to run around with. I kept trying to pick a single species and stick with it for years but finally said "fuck it, my fursona is whoever looks coolest to me today".
For the record, Sergals are not dragons. They are technically aliens with some traits reminiscent of mammals and dragons but live on their own planet with a few other different species. Their lore is actually pretty cool.