I asked on the mod thread and got no response, but I am at the start of a new season and would like to find out:
Can I install startit and still continue my current online game?
Does it effect my ability to also race I the online league?

Thanks in advance.

Most likely no. To see the new schedule you need a new game.
When you install most large overhaul mods many game files are changed. So the old game may get confused.
I would back up my game files before installing. If not on steam.
If on steam, I'm not sure how mods play with steam's auto update.



No clue there, sorry.