Wolfpack,

It sounds as if you are doing pretty well.

Cycling is rather strange. Riding all the time at a nice comfortable cruise will help your endurance but it probably will not affect your top end cruising speed.

I also rather suspect that doing intervals (short intense bursts) will help your max speed some but it might have a limited utility. I believe that to get good at an aspect of riding, you need to rather mimic it out in training - long hard periods, short sprints, hill climbs, whatever. Try to do a variety of things. Of course, if you do intervals, you will probably end up doing longer hard stretches of riding anyway. Good luck.

Also, I would respectfully suggest that you intentionally avoid focusing too much on performance. Working on improving is well work and is often painful to boot. Your bike can easily become an instrument of pain and who wants to do that? I have seen quite a few people train hard then drop out of the sport. It is important to have fun and enjoy yourself every so often and the heck with performance.