Me and some friends want to run this game, can you give us the ability to add multiple people to friend runs so my friends can get the record too?

Nah, just let him submit a friend% run

are alt accounts allowed

yeah

if in the middle of a friend run, and a friend joins u midrun (ex: increasing speed from +0.25 to +0.5), is the run invalid? also, if doing a friendless run, and a friend joins, is the run a friend% run or also invalid?

If friend joins mid run its invalid I think (ex-mod)

technically should only be submittable for friend category if your friend is there during start-end, therefore it is not invalid but a disadvantage to your run not having that best boosts you could have had from the first place. friendless is a harder addition, it's common sense for someone to want a friendless run instead of friend. So whenever your friend joins your intended friendless run, you cannot sumbit that run by friendless anymore. (nerd emoji)

yeh if the friend join in the run

you have to submit it to friend%