Help! Which modifications are the most server intensive?

[noppid]

You should turn on debug and see what the memory footprint looks like.

As for queries, 25 is fine if they are written correctly. Any good hack is going to pull 1 to 5 records on indexes of tables likely cached.

Don't let 15 versus 25 come to mean anything unless you look at the queries in detail. I don't mean to start a query debate. To me, the math rules. Go with the math. No two situations are going to yield comparable results.