yes, tubes slowly leak air. that's normal.

the "blow it up and hold it under water" test is the gold standard for detecting a small puncture. if there's any question, just do it.

I top my tires off with air almost every ride. I also think 130 psi is too high, and harsh riding. I don't think 210 is a lot, but maybe check in the clyde's forum for their tire pressure recs?