Several thousand visitors a second would probably trip the high resource useage if it was continious. A flat/static site may of gotten away with it but anything using a database would of spiked badly. If your site is fortunate to get that kind of traffic and you want to stay on free hosting then a big rewrite would be needed to keep some or rather most of the blog in the client side storage storage area. Note: Do not confuse Client side storage with browser cache they are different
At least that way returning visitors cause less of strain, if they are all unique first time visitors then things get a little more hairy. There are ways of spreading the load around but synchronising the database across several free domains is a time consuming nightmare, so proabably better to go pro and pay for the hosting.
As for PTS being a violation or not I defer to the higher authorities here.