Well one your form is huge. I thought mine were big. I know you did not ask but it seems like it would be very hard for a user to follow. Does it have to be all in 1? Does it submit ok? The attribute table must be very hard to read. What have the users said about the size? For me I broke my project into 9 forms to combat some of this. I launch them all from Collector.
Have you tried pages to break it up a bit?
With repeat_count is does not limit the number of repeats it actually preloads them all. That is why it is taking a bit to spin them all up. Just that one repeat is 400 lines with a ton of lists X how many repeat records. It should be slow if it is that big. I have one at like 300 lines and it takes 22 seconds to load on a android tablet.
Most of your lists are short except fn2a. I do not see that one in the repeat but I may have missed it. If it is try moving it, and maybe some others, to an external choices instead. When I have lists of 5,000 it helps a ton since it does not have to load them right away.
Hope the helps.