Starcraft – Morph multiple gateways into warp gates simultaneously

You have many options here. Many protoss players use proxy pylons placed in strategic locations on the map so you don't have to divert your attention too far away from the battle in order to warp in new units. You can even go so far as to bring a probe with you in battle to make pylons a short distance behind your army to help warp in units and also provide supply for the large army you're creating.

Hot keys can be used to great effect here if you practice a bit. Double-tapping a hotkey will center the screen on that location, so if you have a pylon or other unit near a pylon where you want to warp hotkeyed, you can center location on it with a hotkey, hit W (to select all your warpgates), shift+click a bunch, and then double-tap a hot key to go back to your army in a second or so with practice.

Remember also that it's generally a good idea not to queue units, so warp gates enforcing this is a good way to practice your macro for other protoss production buildings and if you ever plan on playing Terran. You generally want to be spending your minerals on things you get now, rather than things you will get later. This is an important point which is mentioned often by Day9 in his tutorial casts.

Most of all, just keep practicing.

It sounds like you're building a large army and using it to gain map control, but then are falling prey to things like drops and backdooring.

If you have map control your first thought should never be: Crush my opponent, as you're essentially sacrificing an advantage (map control) for an unsure victory (because he doesn't control the map doesn't mean he can't take you). Instead your thought should be: take the map. I think you'll find this change in philosophy will lead to situations where you have a much more powerful economy than him and you're able to kill him with attrition.

Now if you're falling prey to things like BD here is a quick check list for you:

• Are you scouting? an Observer should be the first thing you build out of Robo. If you don't go Robo, a Hallucination works just as well. Sometimes scouting means sacrificing some Zealots in a pointless charge to just get inside his base.
• If you're scouting, are you seeing it coming? Overlords on the edge of your base, Starport with Reactor + 3 Rax, all of these are indicative of certain strategies you should watch out for.
• If you see it coming, how are you responding? If you have map control that means you should be able to respond quickly. Shutting down these back door attempts is often a bigger victory than a straight up conflict
• Finally, Do you have map control? If you don't have map control that means he does, and if he's beating you with map control then your problem is not "how do I deal with a base trade?" but rather, how do I regain the advantage.