Wow! You have been through it and some! To be going through cancer treatment while you are carrying a baby is an incredible achievement.
Just to say that the 'tingles' may be caused by the surgeon having to cut through nerves during the op, so may be worth asking if that could be so. I know it's SO scary wondering if the cancer is anywhere else, and knowing you can't find out until your baby is safely born.
I appreciately, obviously, you can't let CT/ X-rays near your baby, but would it be at all possible to have, say, your lungs scanned (that's the most likely place for any mets to be), if they shield the abdomen properly? Similarly, you might be able by the same token to have a head/neck scan, just in case of brain mets (though if you have no neurological symptoms, even if you do have brain mets, they would be so small as to be able to 'wait' until your baby is born). Again, could you do bone scans of your ribs/shoulders, arms and legs (ie, avoiding lumbar spine and pelvis because of your baby)?
Finally, any chance of an MRI, which, so I understand, is 'harmless' (unless you have magnetic metal in you!) However, I'm not sure if MRI can detect bone mets (my husband didn't have them, so am not well up on bone mets at all.). I assume ultrasound can't see them, or you would have had that done, as I dare say you've already seen pics of your baby by US!
Finally, may I reccoment another source of excellent informatoin on RCC, which is the email group kidney-onc which you can join on http://cancerguide.org/kofaq/. There is a huge amount of collective experience there - though I have to say I can't recall seeing anything about cancer during pregnancy (but it's been running a long time, the group, and there may well be older experience of that combination there).
All the very, very best to you, and I hope all goes well with both yourself and your baby. When are you due?
Take care, Julie.
PS - just wanted to say that although, obviously, these days obs don't like doing X-rays of a foetus, my older brother (post war) had Xrays taken of him in utero (he was breech) and he's grown up very strong and healthy! Presumably they took the Xrays (all pre US days, you see) when he was pretty close to term, and so there was least risk of development being affected. My mother always kept the X-rays, as a 'souvenier'!