1. How does the head size affect your shot?
Larger head vs. small head size? Pro/cons of each?
2.Length of the racquet? 27 inch or go for longer one?
3.Whats the affect of the string tension? Whats the pro/cons of having lower string tension vs. higher string tension?
4.And what are head tape?
1. Larger head= more power but less control
2. half an inch won't do much of a difference, add half an inch of reach and the weight distribution crap
3. lower string tension will make you hit the ball harder but less control
4. I think you mean lead tape and it is used to add some weight to your racquet
If you want to buy a racquet enter a demo program if you have it available and just try some racquets, don't be fooled by who endorses it or anything thats right just use the one that's right