Man - and here I was just about ready to post the updated rulebook. . .OK, I'll calrify both of these points in the next version. My take would be:
1) Yes, German and Italian naval units can be repaired at each other's shipyards.
and
2) ships being repaired do not count against maximum build limits - they are ignored for maximum build limitations.
Thanks for pointing these open questions out !
at some point these rules will be air-tight
Mark