Leos store extra fat in their tails, so while it's probably possible to over-feed them in the long run, unless he's having trouble dragging his tail around I wouldn't worry about it! At his age he's still got a lot of growing to do. As long as his tail stays nice and plump, you're doing just fine!

When I used carpet I tried to give it a thorough washing every 2 weeks or so. Since you're spot-cleaning it every day, you might not have to do it so often.