re: Higher orbit or big 8
I've read Gemini 12 was also supposed to have been in a higher orbit (with Buzz opening the hatch while in apogee) but the Agena had a problem and this plan was dropped.
If staying even for a little while in the Van Allen Belt is to be avoided, but testing the equipment and the humans away from Earth should happen, then perhaps the easiest way is by going all the way around the Moon and back in a free-return trajectory....