Hi
I am sorry you are having troubles. First let me say excellent job on getting your LO on EASY, that it self is not easy (pun intented ;-)
How do I increase this first awake time without him getting overtired and being difficult to get to sleep? He often resists going to sleep even though I act very quickly on his sleep signs
This really difficult, so i understand why you are having trouble. If you are on 4hr EASY and 45min naps, feeds and naps will collide at some point in the day. So your schedule will look more like EASY, AS - EASY... To answer your question, i don't think you can increase is A time at this age. He is just too young.
he can then last about 1 1/2 hours-2 hours
that sounds really long for a 10 wk old, this long A time could be contributing to the 45min naps. I would think 1.15 tops would be appropriate for his age.
Also for those short naps:
-do you swaddle
-use white noise
-try to extend these naps w/ either wake to sleep or pat/shh?
I am sorry i don't have a direct answer for your question. It sounds like you are doing a great job but he isn't ready for longer A times yet. Wait until he is 3-4mos.
Hope this helps some