It's been a while since I used Inv5, but I think this will work.
Activate the part into which you want to place holes. Then using 'project geometry' button, pick the round profiles of the holes you need from the greyed out mating part(s). When you return from sketch mode, you can use the cut...
You can change the text alignment using the format menu item and styles editor. Choose dimension style then text tab, then vertical alignment. The middle choice will show in-line vertical alignment. This should solve your problem.