She still will not take a catnap or a third nap- but she will be increasingly needing to be held in the evening
This is likely the 3-2 nap transition. It is not unusual for babies this age to only take 2 naps. But of course transitions can take time for babies to adjust to. It can be so frustrating, they don't want to take the 3rd nap but they get OT without it. With the increasing of AT and improving naps the routine will morph into a 2 nap routine that your baby will be better with.
but she is now waking up every 2 hours all night long- insisting on eating. I'm worried that I'm setting us up for a new routine of eating all night.
It is possible that the night feeding has or will become habitual. Breastfeeding can be so challenging. We are told to breastfeed on demand, but babies know how to manipulate their mamas and will often nurse for comfort and habit. It is not unusual to have a night feed or 2 at that age and some babies can go without night feeds around that time. After I dropped the dream feed (at 8 months) my LO would go from 7PM-6AM with out feed.
How many milk feeds do you have during the daytime?
The night feeds... does she take a full feed? Or are they quick feeds?
Assuming some of the night feeds are habitual/comfort I would recommend working on one feed at a time. Give yourself an hour(s) minimum for first feed. It looks like she does some clustering in the eve, maybe say 3 or 4 h, so decide not to feed 2h after you PD for bed. I would send hubby in to do the settling so she does not expect milk. The next time she wakes you will probably have to feed her, as with the other night feeds initially. Do this consistently for a few days, this will give her the opportunity to compensate during the day if she needs/wants more milk.
When/if this works for you, you should then maybe look at the 3rd wake up (you fed for the 2nd) and replicate same process giving your little one a few days to compensate during the day.
It might also be that she is working on standing without holding on?
Don't underestimate the sleep disturbances that new skills create. It may not be the full cause of any sleep issue but it sure can contribute!! Any time my LO was learning a new skill I became a "skill practising tyrant" during the day... OK well I am not that mean, but I put extra time during AT helping my little girl practise those skills. For one it tires her out good for naps and she is less inclined to practise in her crib, as she had lots of practise during the day.
Teeth are also a huge pain in the A$% at this stage too. Babies either want to nurse more or less during teething eeeek!! If it is not one thing it is something else.
I'm not sure if a more structured schedule that is clock based would be better?
I would jump to a rigid schedule just yet (although the older they get the more comfortable they may get with a bit more structure).
I think you are on the right track with increasing the AT. There is still room to push AT to reach the AVG AT for her age. Your first nap isn't too bad for now (anything below 90 min is usually considered UT). Your 2nd nap is shorter, so you may want to push that AT a bit to try and lengthen that nap. But overtime you will likely have to push both AM and PM AT. They will not necessarily be the same. Some babies like longer AM AT and others like longer AT in PM.