It's doable, and the Alpha has a really low stall speed and some of the softest stall tendancies I've seen, which can help you a lot here.

I'm assuming you will have someone throw for you. I wouldn't try to solo launch a .40 size plane that wasn't designed for it.

Definatly get rid of the stock 3-bladed prop and replace it with an APC, an 11x4 or 11x5 would be ideal, a 10x6 or 10x7 would work. All of those produce much much more thrust than the stock prop, and you're going to need it. Bring extra props. You're going to need them too. The Alpha with the Evo engine has plenty of power for this kind of thing, btw. A typcial trainer with an OS .40 LA, on the other hand, would be a real trick to handlaunch, but still doable.

For an experienced pilot, the launch angle isn't that critical, but close to level is best. I actually prefer steaper launches, sometims up to 45degrees, but I also am already leaning on the down elevator at launch, and usually have more power available.

When throwing, take a couple of steps and give a smooth, solid shove and follow though. Don't "snap" it forward in a sudden hard throw, the fuel will rush to the back of the tank and the engine will sag and loose power.

Depending on your landing area, consider ditching the landing gear from the plane. If you're hand lanching anyway, it's just deadweight, and on a hairy launch over obstructions (tall grass, etc), it's 5-6" more of altitude in your favor.

Use all your altitude if the launch is slow. Don't be afriad to push the nose down and trade altitude for airspeed. If the launch is too steep, push down hard and dive for airspeed. From a typical overhand launch, you should have 5-6 feet to work with. Sometimes, you gotta use most of it.

Don't panic. Airspeed is your primary concern followed by altitude. It's better to flop in flat a few feet away from launch after a shallow dive that wasn't quite enough than to claw for altitude and fall off on a wing and cartwheel.