VB is not only sufficient for very complex programs it is also (imo) the best because you can develop very rapidly (clear language definition, good IDE and debugging features). C++ is unnecessarily painful (sure it's faster and you can do funny things with the system but that's not needed for trading. Much longer development cycles). Clearly also to recommend: - Program for an API (like IB, AmeriTrade or others) - Do not program for a platform (like TradeStation etc., it looks at first like the easy way and it is but you pay with severe limitations)
Actually that's not true for every platform. Tradestation is extensible thru a DLL interface....which provides interopt with Excel as well as the Windows API.
Sure, technically you can do many things with TS. But if TS is something made for you depends heavily from where you are starting: - If you have already a working strategy that gives you reliable signals so that you don't have to spend the 100$/mo then TS will be ok. - Otherwise there are many ways you can get data and API quite cheap or even free. Without a working strat TS would only suck you into premature trading which would lead into loss.
TS is ok, but not for HF, rapid fire tick trading. If you seek 1min bar trading or slower TS should be fine and it is easy to learn to program. True, a hundy a month cost but if your trading that should be negligible and they waive the monthly if shares reaches a upper limit.