Hmm, you might ask the vet about switching to buprenorphine. A lot of people find that their kitties respond to it better than to Tramadol or gabapentin.
Is the amlodipine being given to try to slow disease progression, or for high blood pressure? (And if she hasn't had her BP tested, she should.)
The potassium looks good; the vet likely didn't say anything about binders because she recommended the renal diet. Take a look at the food table on Tanya's site and see if Lili will eat any of them.
I'd call the vet and try to get more Cerenia as soon as you can, because it works best when given consistently, and it's clearly helping. What is the dose she's getting? When given by injection, the dose is 1 mg/kg, but when given orally, it's 2 mg/kg, or approx. 1 mg/lb. Many vets prescribe the injection dose for the oral Cerenia as well. If Lili's underdosed, you can show your vet the ISFM Consensus Guidelines on treating CKD: SAGE Journals: Your gateway to world-class journal research
The dosing is in table 9, p. 232.
For pilling, try putting the pill in one treat or Pill Pocket and then putting it, along with some plain treats as decoys, on a plate. That way she won't feel like you're doing something to her that she doesn't want done. Celia resisted any treatments ferociously, but when I put them down like treats, then it was her choice to eat them (you know how cat are...). She didn't like Pill Pockets, so we used cheese. She was so incredibly suspicious, but the key was to use just enough to completely cover the pill. If it's too big, you risk having Lili chomp into it, and then she'll forever be turned off by that treat.
I'd also try adding Cosequin. It's a chicken-flavored powder that Celia would usually take if I mixed it into her food.
If Lili is already a fussy eater, she may not like the k/d anyway - most kitties don't. If you don't want to feed it, then as far as the vet knows, Lili doesn't like it...This may not be a lie anyway.
As for how to encourage Lili to eat - that depends a bit on whether the nausea/vomiting are controlled. If they are, and she just doesn't have much appetite, there are plenty of things you can try but a few easy ones are sprinkling some Fortiflora, or dried bonito flakes, or crumbling some dehydrated chicken or salmon or whatever, onto her food or mixing in a bit of plain meat (nothing added) baby food. Celia liked roast chicken, and I'd also boil a chicken thigh and give her bits of chicken in some of the boiling liquid. That's also a great way to get more water into a kitty.
Is she vomiting any white foam? That would be a sign of stomach acid, in which case famotidine (Pepcid) or ranitidine (Zantac) would help.
I hope you find some super yummy things that entice Lili!