I use to compete when I was younger.
I understand you don't want Olympic grade so I'm going to give you only 2 pieces of extremely valuable advice.
1 - Table - Don't go under 19 millimeter thick - If you are in the US aim for 1 inch thick if you get a good deal.
2 - Only buy 3 star balls (Stiga or Nittaku) - Cheap balls are an abomination.
"Does the bounce height regulation thing really matter?" not needed for you. But stay above 19mm.
Happy Ping-Pong!
-Don't put drinks on the table. Especially if you buy cheap (paint will be cheap too) -> Liquids can ruin high density fiberboard