AbigailII:

Tournament creation 1) players bring in their own chips (as is done now for the
existing poker tables) and 2) tournament chips are not related to the total
number of chips a player owns - you get a number of chips to play with, and
they're gone afterwards

How about a mix: You pay a tournament buy in - for example 500 chips - which is deducted from your chip balance and put in a price pool, and you receive tournament chips - for example 10k - which are not related to the chips in your account. Then the tournament could define a payout structure - for example, the winner gets all, or 70%/30% for 1st and runner up, or something similar. The payouts are then awarded from the price pool back to the winners' accounts.

More tables
If a tournament has 10 players or less, the tournament can be played
on a single table. Otherwise, the tournament has to start on more than
one table. As soon as 5 (or, in rare cases less) players are left at a
table, they advance to the next round (keeping their current number of
chips). Repeat until there's one table, with one winner left. Of course,
another cut-off number could be picked as well (perhaps only the top
3 should advance).

That is one way to do it, called shootout tournaments. There is, however, a more common practice of moving players to other tables until there is only one table left. For example, 20 players start a tournament, and there are 2 tables with 10 players each. Once 2 players get eliminated, tables are balanced. So if there are 8 players on table A and 10 players on table B, one player is moved from table B to table A. Once only 10 players are left, all players from table B are moved to the free seats at table A, and the final table is played out. This is however more complicated to implement and test, so maybe shootouts should be the way to get started. Oh, and all other suggestions you made are good. Usually blinds are increased time based, but for BrainKing I think it would be fine to do it based on No. of players or No. of hands. I actually think, No. of hands would be better. But please don't do it based on No. of rounds. That way, when there are only two players left, blinds would increase every second hand, not good imo.