Improving the back suspension a little will just make the front squishing a little more noticeable. Nothing bad will come from this change mechanically. You'll just want to spend more to adjust the front end
When it's time to do that, get some ex500 springs, a little heavier fork oil, and some pvc to make up the space in the shorter spring, and you'll have a little better front end feel to match that little better rear end. It's a good budget way to improve the suspension a bit.
No worries on the weight thing; I'm not judging anyone on their weight until they judge me on mine.
You're also comparing yourself to me, a 20 year old college kid who rides a road bike as often as I can, and fills in the off-days with running. In the summer, I substitute trail rides on my mountain bike for some of those road bike rides. I'm 5'10" and built like a bean pole who runs; it's a blessing and a curse. Some girls like lean guys, some girls just like big arms and chests
