I'm trying to craft the Tetsucabra S armor set for high rank, but I cant freaking find any Rhenoplos in high rank anymore.
I had to look it up because I'm kinda having the same problem, since genprey show up where rhenoplos usually do during the tetsu
farm fight. Apparently they will show up on sunken hollow harvest tour (I just checked now and it's accurate info). If you haven't unlocked those already talk to the 'pro hunter' near the wyceum (head towards the camera in dundorma) and do their quests and eventually you'll get the harvest tours.
For damage, again, Kiraniko is your friend.
Stealth Glaive versus
Usurper's Boltslicer. As you can see their damage values are different but where it says "true attack" is where you want to look. Then that 'true attack" value is further changed depending on the individual attack you're doing. Great Sword's fully charged overhead swing has a higher multiplier than the its blade slap, for example. Normally the values for each attack would be listed there but there are something over 200 individual attacks in the game now thanks to the new midair attack system so it'll take time to get the info.
If you click 'moves' on the top right of this page you'll see an example of how each attack modifies the actual damage you do. The info is for 3u but it should be fairly relevant still.
EDIT: You can actually still see the move list multiplier but you have to guess what each move is since right now they're just move ID's instead of properly identified. They're on the main page for each weapon.