Day sleep certainly does affect night sleep for most babies. Since he is on the short side for day sleep, his overtiredness could be causing his early waking. However, since he is going back to sleep (until 7:45 I assume), it might just be his growth spurt, which can last up to 2 weeks.
Your EASY routine looks great. One thing to consider, however, is that you should take note of the time he wakes from his nap, and put him down for the next nap based on that time, not the time after he has his bottle and A time. For example, if he is able to handle 1.25 hrs of A time, his first nap ends at 9:45, then his next nap should be about 11. I realize that seems very close to the feeding at 10:30, but as long as you are not feeding to sleep, then you are still following the EASY principles. If he still has a short nap, he might even end up with a cycle that looks like EASASE. This is very common until babies can learn (with our help) to transition in the sleep cycles and sleep more than 1 cycle in a row.
Also, as you mentioned, bringing the df forward to closer to 10 pm might help as a late df can disrupt the night sleep pattern and confuse his internal clock.
I encourage you to browse the Sleep Forums, especially the Night Wakings Board for suggestions as to handle early am wakings at this age. If you cannot find a post similar enough to your needs, you can create one and copy the link to this page so that you do not have to retype everything. If you need help with that, let me know.
