I don't see a problem with just waiting until we finalize the amount of teams, people will still have plenty of time to pay while we're finalizing the details.
We should start working on rules though, those always take forever and start dumb fights.
Some off the top of my head from other league:
Overall:
Tanking rules?
Size of minors in all sports?
Punishments for playing someone elses minor leaguer?
FAAB? If so, how much? Tradeable? For all sports or set amount per sport?
NFL:
Roto or H2H?
PPR?
Number of WRs?
Number of Flex?
Bench size?
Points per passing TD?
Consolation bracket?
MLB:
Roto or H2H?
Number of starters?
Number of OF?
Add MI/CI?
Max innings?
Min innings?
What CATS?
NBA:
Roto or H2H?
Number of starters?
What positions?
Max minutes?
What CATS?
Draft:
Draft or assign year 1 draft slots?
If assign, how?
How long is timer?