1) Most plants do not grow as well in sand as other substrates because the debris(poo and stuff) do not get down in the sand like it does gravel.
2) when siphoning the sand just hover over the sand and the siphon will pick up the stuff laying on top. Sometimes I pick up a little sand but not enough to matter.
3) If you have Malaysian Trumpet Snails (MTS) you do not need to manually stir the sand. They do a wonderful job of stiring it up for you. Usually when I'm seeding a tank with MTS I put about six in and they take it from there.
I love my sand tanks they are much easier than the gravel substrates because I can see when I have all the junk out and I'm never sure about the gravel ones

. Just yell if you need more information.
Carol