Re: Is it better in the long run to just go for your shots?
Manutoo, if you want to be really good in a few years time, and it sounds like you do, you need to practice hitting hard shots accurately. Then you need to go for these same hard shots in some practice matches. It doesn't matter whether you win these matches, they are matches where you will learn to hit hard and accurately under some pressure. Then you need to do the same thing in tournament or interclub matches.
If you hit safe all the time, you will never learn how to hit hard and accurately under pressure. But if you follow my advice and hit hard in matches, you need to be learning all the time, so that you become more and more accurate with those hard shots. You can sacrifice a few months trying to learn how to hit hard and in. But at the end of those months you need to be much better at going for your shots and getting them in. It should feel something like :"I used to miss my DTL forehand if I hit it hard, but now I hit it just as hard and get it in, cos I've been practicing it every day for half a year." If you don't go for your shots you just will have never practiced hitting hard, so you won't be able to do it very well. Hitting hard and accurately is a skill, and like all skills it must be practiced. Most players will never acquire this skill, and it won't matter to them because they are only playing club tennis. But if you aspire to more then you will need this skill.
However, you have to be mentally strong to do this, because you will almost certainly lose matches for a while if you suddenly hit harder. If you hit your serve 60mph, and you suddenly try to hit it 100mph, you will miss a lot of course. But after practicing hitting it 100mph for a while you will be able to get it in. The key is to lower the error rate by becoming more accurate (so basically becoming more skilful). Also, you will need to figure out how to hit hard with less effort. If your technique is smooth and whippy, the power will come more easily. This will help you to have control when you hit hard. If you are always straining, then you will not have control. This is also difficult, since at the beginning when you hit hard it may feel strained. You will need to learn how to use a relaxed swing to hit hard. When the power comes automatically, easily, and without thinking, you will be able to think about how to control it, and then you will have reached a different level. This means you may have to suffer a few months of being not so confident (or a shorter time if you improve rapidly), but as you master hitting hard and accurately you will become more and more confident.
My advice also assumes that you have enough talent to figure out how to hit hard and consistently under pressure after some months of practice. But if you are determined I'm sure you will figure out how to do this.
The other option is to be very, very fast. But unless you are in the top few percent of the fastest people in the world, you are unlikely to reach a very high level purely through footspeed, since good players will often be just as fast as you. Also you can just be very consistent, and then you will be a very good club player, but no more, since higher level players will also be quite consistent even when hitting hard.
Of course, you will also need consistency. But if you have high goals, your aim should be to become consistent when hitting hard and near the lines.
Good luck with your tennis!