Not bogus (those are pretty trivially rejected by distributed nodes), but you could certainly flood it with valid microtransactions, and thus jack up the fees p

Not bogus (those are pretty trivially rejected by distributed nodes), but you could certainly flood it with valid microtransactions, and thus jack up the fees people have to pay to get their tx validated in reasonable time. This activity, way more than actual block size limits, underlies the ridiculous fee escalation on BTC that someone else mentioned.