Can every class jump from the deck onto the round canister and then onto the point? If yes, then just build a (thin) bridge from the deck to the capture point. People generally don't like that type of jumpy stuff. Though I suggest keeping the round canister there anyway, to add to lower-level gameplay.
all-in-all, a very good start, keep it up!
EDIT: I suggest you change the name for your map though, there are multiple other Plateau (name) maps out there, tf2stats.net will help you out with choosing a name.
a search of your name brought up these:
http://tf2stats.net/map_search/?search=plateau