I just want to offer some ((((hugs)))). Babies can be so frustrating! But I also want to say you sound like you're doing a FANTASTIC job observing your LO and recognizing his particular patterns!
My LO was always a guzzler too. Turns out it was because he had reflux, which didn't get diagnosed until 4 months old. The amount of time eating shouldn't affect your EASY to much. Basically, I look at AWAKE time (which is how lots of BWers do it, I think) -- which just means you look at how long your baby is awake from start to finish, which includes both eating and activity time. Don't fret on how that awake time is divided up into eating and play. it's all one, really and truly. That should not affect your EASY.
The 3-4 hour EASY depends a lot on when your LO is ready to eat. By this age, moving towards a 4 hour EASY is usually what happens, but yours may want to try 3.5 hour or something in between. The time is dependent on him: how long can he go between feeds. The signs that a LO is ready to stretch that time is feedings start going off (eating less in early part of day, more later part of the day) and short napping.
The 45 minute naps is a REALLY common thing at this age. I think just about every baby goes through. The reasons are many, but one of them is that their REM/non-REM patterns changes around this time to one that they will have through childhood. That means when they wake after that 1st sleep cycle, they have difficulty putting themselves back to sleep. They need us to teach them how. It seems weird that it happens now when maybe prior to this your baby was able to go back to sleep on their own (or maybe not! depends on the LO), but it's very very common. We had to do it, and after I taught him at 3 months, he has retained that skill through all the ups and downs since then: teething, shots, growth spurts, etc. There's lots of information on how to do this all over the board, and I'm sure one of the moderators can help you, or I'll be back with more info. Basically the 2 main BWer techniques are wake-to-sleep (WTS) and holding the baby's limbs down through the jolts at the transition point. Both are temporary measures, and after 3-7 days you'll usually find your baby transitioning sleep cycles on their own.
As for that first awake cycle being short, that requires some more information. Can you post a typical routine? It may be that your child is using that first nap to extend night time sleep. A little more information will help.
Do not despair! The great thing about EASY is that it is adaptable to YOUR LOs needs. It's just a predictable series of events - there's no need to be chained to the clock. It sounds like right now your main problem to making it a consistent routine is that your naps are short, not that the eating time is short.