Advice for new sakura/cherry tank

I noticed my shrimp don't do too well in my community tank so I will set up a shrimp only tank. Right now I have a 2ft tank, a sponge filter and driftwood with java moss. I still need to get substrate and some other plants before it's set up.

1. Any suggestions on which substrate I should go for? My community tank uses fine Sudo sand (for my corydoras) so should I use that again or should I consider soil or gravel? Is it necessary to go for ADA or Gex soil?

2. Are these Seachem products safe for inverts? Prime, Flourish and Excel? Because I dose these on a regular basis.

3. I don't intend to get a fan or chiller. I read that sakura and cherry shrimp can tolerate slightly higher temps than other shrimp, is this true?

4. Lastly, how often should I do water changes and how much to change?