Hi there and welcome to BW forums
Your routine looks pretty good.
Let me see if I can answer your questions
he has been able to keep with 3-hr interval between feeds but at time, he will wake up and scream to be fed at the 2-hr mark.
I don't see this in your EASY times but if he is screaming for food you should go ahead and feed him certainly.
LOs can cry for food earlier than expected maybe through a growth spurt or sometimes due to gas pain or reflux. I wouldn't be concerned about just the odd time, if it is all the time it might be worth looking at again. From your times though it looks like he is going 3hrs+ and two stretches of 4hrs at night which is great.
1. Do I wake him up from his 4th nap (or catnap) to try to preserve bedtime at 7pm
You can, yes, so long as it is working for you and your LO this is a good routine. Your last nap times may end up different if the first nap is longer of course so you might not always need to wake him up to maintain BT. I wouldn't expect him to be hungry at that time based on his previous E time but if he is that fine too, just feed and then feed again at BT (I realise those two feeds almost run into one as they are so close together. Feed, BT routine and feed).
2. If his second night feed is close to his wake up (5:40am-6:10am), do I still wake him up at 7am. He was not interested in eating at all and I could barely get an ounce in him. He was still quite sleepy.
Some people prefer to let their LOs sleep until a natural WU time, but it can effect the day and give less consistency overall. It is your choice but I would suggest you don't let the morning WU time become *too* flexible. Maybe 7.30 latest just to get into a predictable routine for you both? It doesn't really matter what time the WU is so long as it is relatively consistent.
I would still offer the E on morning WU as he learns that at this time you wake up and get food, it may help him work on a longer stretch of sleep over time. I wouldn't worry if he is not particularly hungry though and if he takes nothing or almost nothing just count the previous E as the E time and add 3hrs from that. In this example he would be fine until after his first nap either because the nap is short (S 45 min, E 3hrs) or if the nap extends he will just wait a bit longer before eating (S 1.5hr E 3.5hr this is no longer than he does at night and he has also been offered food between). Either way he is likely to eat when he wakes from that nap and you begin another round of EAS.
3. THe dream feed doesnt seem to be working for us. i wonder if it's better for us to do a 2-hr cycle at bedtime (feed at 9pm and again at 11pm) to tank him up? Would this work?
I see no harm in giving this a go. Is it because you'd prefer to feed him asleep rather than have him wake up at 10 for the feed?
Mine always woke for the feed and we kept a 10pm feed for months, just like a DF, weaned at the same age as a DF too.
Either is fine. If you wanted to try the DF again you can just try 20 min earlier and see if you catch him in a different phase of sleep when he might be more willing to take the feed.
hope this helps
please do let us know if you have more questions