A lot of new radios have automatic tone ID. If both tones are the same, they only need to be within receiving range of the repeater. If the tones are different (or only input), they would have to be within range of someone transmitting to the repeater, but it is automated these days. No longer necessary to just quess.
Will you notice a difference in the antennas? At normal effective GMRS fars, probably not. Going for super extended mountain top to mountain top with antennas out of polarization angle agreement, yes.
Sorry to hear about the poison oak. First time I got it was from running a motorcycle off the pavement and ended up under the bike in a ditch full of poison ivy. I had to clear a LOT of poison ivy last weekend and ended up with a piece inside the work gloves I was wearing. 67 years old and it still only gave me a single small blister were I had a repeated hard contact. Doesn't mean I won't break out into a bad rash the next time.
Be warned, where to get the best pizza seems to bring out hams on 2m repeaters. Congrats. Got for General ASAP, it is no harder to do than Tech and there is overlap in the question pool, you could already accidentally pass it on a lucky day.
WMPT is cranking a meg these days. If I recall correctly, they had a temporary experimental licensed increase to 2 for a few months.
My father bought a beam/yagi so far back I don't remember not having it. Probably on advice from my godfather who was a navy radio tech in the very early 1960's.
As I understand it, that is to the physical visible horizon, but RF propagation usually follows the curvature of the Earth some fraction beyond the visible horizon.