Even if no body works exactly like the other it is still a simple truth that you have to run faster to run faster, nobody will significantly increase speed if he never trains for it. If you do that by long jogs or interval training again is a bit a philosophy and preference question.
The Endurance training around 75% Hfmax is the foundation for pace. Without endurance the ability to run fast will not help much as you will not be able to hold it up for longer periods of time. But all of that training can also be done pace based as the relationship is true in both directions a certain pace equals a certain heartrate so you can use one or the other to control your training, for me pace is easier, but that again is individual preference.
Resting heart rate should go down with improving cardio vascular fitness. Also your Hfmax should best be tested and not only calculated if you want to use it to steer your training. Hfmax calculators you find in the net can only give an indication, individual values can deviate quite a bit ( my husband e.g. has a Hfmax about 40 beats higher than calculated for his age, so relying too much on a calculated value could mess up your training plan quite a bit)
Nebulus a friend of mine uses a TomTom watch, my husband has a Polar and another friend uses Garmin all of them are pretty happy with their watches. I found the following blog quite helpful for helping me chose my gear www.dcrainmaker.com