Hehe your Cloud looks like he's pissed off!
Your page of experimenting reminds me of some of the doodle pages that I do. They are normally filled with loads of different style eyes and faces. I think it's a good way to practice actually because you'll find a style that suits they way you draw. I would suggest you do pages like this whenever you can, even if your stuck on the cash desk at work, just grab a bit of paper and doodle!
The swords and guitar bits are cool. I really like the sword actually. It reminds me of a mixture of a DMC sword and one of Tidus'. I always try to stay away from drawing weapons mainly because I either do some boring Katana or I find what I do draw looks unoriginal.
Your 3/4ths drawing is good. You're definitely starting to get there, you just need to practice more. I know it's hard with lack of time and stuff. I normally try to draw at least once a week. I keep telling myself I'll start drawing once a day but sometimes I feel too tired to get any idea's out. It might be worth you finding a basic anatomy tutorial to help you get some of his body parts more accurate. Something like this might be quite useful:
AnatomyI know you don't use the anime/manga style but the basic construction is there and you can apply that to your style. I even started using this kind of technique because I was getting so bored of drawing characters in the same style and knew I needed to progress.
Keep up the hard work and most of all keep practicing and you'll feel confident enough to start your web comic in no time. I just hope I've been of some use!