I try to ask it in their telegram group, it's clear that has no minimum to join the staking pool, the more you have, then it's more better.
https://t.me/PoolzOfficialCommunity/172904 So I think the answer is yes, you can join with 5 POOLZ token.
From what I understand, the token pool limit is 1,500,000 POOLZ, so once it reaches the limit, no one will be able to add more.
Yes I have also asked the team yesterday and I have also joined staking, I only hope that POOLZ can exceed the $100 price in the future, now I can only try to get more POOLZ