the algo is CPU weighted and botnets actually help secure the network. (Though they may be ethically wrong)
yes the chain is heavy, however, to do mixing correctly means you use more txs and end up weighing just about the same
have you counted every bitcoin tx to verify they add up or do you rely on the software to do so? I would say most people rely on the software and the Monero software can count up the Monero that exist as well. So as long as there is no inflation bug in the software, we should be fine. And there’s no indication in the Monero price of such a bug.
Edit: To add to point 3, either an inflation bug has not been found, or if one has been found, the person has done a very fantastic job of going against human nature and not selling a ton of Monero that do not exist for profit.