Between the manual and a lot of practice I'd managed to build and repair a bunch of stuff with my MIG. It was several years before I took some classes and sure wished I'd done it sooner, I'm sure you'll pick up lots of useful techniques and tips. The intro classes working with stick and O/A gave me an appreciation of forming and controlling a nice puddle and that carried over to improving my MIG. I'd say it's much easier to produce a useful and decent looking weld with MIG once you get a little feel for setting up the machine (voltage & wire feed). The class will give you all that info and some good practice. You can use both hands to operate and guide the MIG gun so you should be able to steady everything ok. I'm a lefty so I hold and operate the MIG gun with my left hand on the trigger. I steady and help guide the nozzle with my right hand, usually resting on the work or another guide. I'm generally don't work on anything over 0.125" so I usually use the lighter TIG style gloves. I find it easier to control the MIG gun with those than the heavier stick style gloves.

You're right about having better control with TIG but it's a bit more of a learning curve. You can TIG with or without filler rod but in most cases you'll be using filler and both hands will be busy. The tungsten electrode is close to the puddle and you can't dip it in the puddle or hit it with the filler rod while you're welding. Takes a pretty steady hand and practice. I think you'll be less frustrated and be happier with the initial results with MIG.

You can also O/A weld with or without filler. The classes generally start with just running bead without filler, then make beads with filler, then start making different joints in different positions, etc. You also get a lot of control with O/A welding since you have some control over the amount of heat and filler that you're using.

As far as aluminum, I think that having the right equipment is very important. My initial attempts were trying to MIG some aluminum using my little 120V MIG. Not easy or pretty with that setup and I'm glad I learned there are better ways before I tossed it under a truck. I had a chance to attend a demo night at a local welding shop and the Lincoln rep had a high-end MIG unit set up just right to weld aluminum. He had us trying T joints in aluminum strips probably around 0.045 thick. In my first try I ran a beautiful looking bead. In that case it was 90% machine and setup with maybe 10% skill on my part. At the CC classes we had some nice Miller Dynasty 300 TIG welders. With a little practice and coaching I was able to run some nice stack of dimes beads on aluminum. I was also able to build a couple of projects including a small toolbox I was very happy with. It can take a long time to build enough skill to produce consistent results with a variety of joints in different positions but with the right equipment, coaching and practice you can do some pretty neat work.

Have fun and practice, practice, practice..

Hi-
I fear that you are getting some confusing information from somewhere.

First SMAW is one of the most versatile of processes. With it you can weld many materials by simply changing electrodes. There should be no degradation of quality when using this process on materials for which it is well suited. It is all around you in pipelines, bridges, buildings, vehicles and lots of other things. Although perhaps not ideal there is no reason that a skilled operator with appropriate electrodes could not use this process to build a motorcycle frame.

Oxy acetylene welding is an obsolescent but still useful process for the user who has time for it. It is very similar to TIG from the welders point of view in that it involves a heat source in one hand and filler (usually) from the other. Being left handed myself I doubt that you would feed the filler with your left hand, more likely you would hold the torch in your left and feed with your right. You may be surprised to find that when you weld your tremor disappears, it does for some people. You should complain to your doctor, perhaps some adjustment is possible. Lots of airplanes, including military planes, with tube frames were O/A welded well into world war two.

Practically every welding shop has O/A cutting equipment, any course you take will show you how to use it.

TIG is very versatile, can weld materials that are impossible with other methods. It isn't very fast. It also requires two handed dexterity.

MIG (also flux core) as you say feeds wire from a spool so there is only one hand working, that leaves the other to provide stability (also true for SMAW). Its advantage is it's fast. Its disadvantage is also that it's fast so you can bury your mess before you even realize that you've made it. Its really easy to make nice looking welds that have no fusion at all with the underlying metal.

If it took years and years to learn to weld aluminum those welders could demand wages of hundreds of dollars per hour. On the other hand if you do any of these processes for years and don't learn something new on the last day you just aren't paying attention.

I, as others have, recommend that you take a course. Go with an open mind. Play with anything they will allow you to touch. Even if the material presented isn't exactly what you wished for you will find that it transfers into other processes better than you would have thought.

Bill