Your routine looks terrific...well done
...and if she's a bit fussy at bedtime but sleeping well..then it will probably sort itself out with time and consistency. You get a big gold star girl...many would kill to be in your position!!!
Here are some suggestions to see if it helps with the bedtime fuss:
1) keep the bath coolish...too warm and it can be too stimulating. Some babies just find a bath too stimulation full stop...if so, eliminate it.
2) if you wanted to try the swaddle just to see if it helps you could do a few things. Swaddle for last feed and when settled/drowsy - remove it and put into grobag. OR use a light muslin swaddle and a nappy only. I know what you mean about the heat...I'm in a hot climate too and also use the grobag...but on bad nights I go back to the swaddled and nappy only.
3) Play around with the last A time and see if an earlier bedtime helps. It could be that she's a bit OT (or UT) by the end of the day and maybe just 15 minutes less (or more if that doesn't work) will do the trick.
4) Finally - the 45 min catnap might be an issue ...but I doubt it. At 4 months this looks spot on. You could just try limiting to 20 minute bridging nap.
A few things there to think about. Let me know what you think.