It doesn't make sense!
Why I think so?
There are two main reasons:Firstly, limiting total post per day for each users is not smart option, because when people have ideas to discuss, to contribute, to help others, they should have right to compose and publish all their ideas via threads. Limiting total threads per day will seriously violate the basic rights of forum users.
Secondly, even spammers, they will not spam 20 or 50, or 100 threads per day. It is the fact because they spam only for getting postcounts in order to satisfy their bounties' requirements. So, it doesn't make sense for spammers too.
Do you think that it will be easier for the forum if there will be a limit as to how many posts a members can make in a day?
The example here is not equally treated all forum members, obviously.
I don't think that a Ledgendary or Hero always has better ideas than lower rank users, including Newbies.
There are many many trash higher rank users due to the old rank system easily allows them to rank up.
Those types of high rank users don't be able to contribute valuable ideas/ discussions/ contributions to the forum. They always collect postcounts for their bounties, nothing more.
For example, a newbie can only make 5, a Jr. member can only make 10, until members reached full member or sr. member or other higher status? Maybe it will help keep the spamming to a minimum, and would encourage a more meaningful topics and conversation. What do you think?
In a nutshell, I don't support your ideas because they are not a realistic, meaningful new rule for the BTT forum!