Yes. You need to mine to create the new block but mining blocks and blocks generated by burning of coins are not depended. One block by mining is 50 SLM and by burning is 250 SLM. Of course this is depend from difficulties. Bigger difficulties means less block reward. Maybe d5000 or Graham can correct me.

For the staking i dont stake every day. After a few month i activate staking than one time coming all stake coins so i dont have a problem with CPU usage.

By my experience if you burn 100 000 SLM, in 3-4 months you should have return and all the rest is pure profit. For this your wallet has to be open all the time.