I’ve been reading this board and as an aerospace engineer, thought I’d give you a “rocket jockey’s” opinion. If someone came to me at work and proposed a telescope on the moon, here’s what I’d say.
There are a few problems with it.
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Getting it up there. You would have to have a couple of communications satellites orbiting the Moon to get info back and commands to it - remember, it’s on the far side of the Moon. Then, you’d have to build it, have it crash on the Moon, deploy, possibly more than once (if it’s really big), then assemble itself, all while maintaining extremely tight tolerances and not breaking or smudging anything. You could have astronauts help, but that wouldn’t necessarily make it any easier. IMHO, it would be easier in micro-g (no crash, no gravity to distort the dish/lens/mirror).
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RADIO pollution has nothing to do with an OPTICAL telescope - different parts of the EM spectrum. Not my area of expertise, but if I remember correctly, the atmosphere doesn’t really interfere that much with radio waves, so you might as well stay on the ground for a radio telescope.
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And here’s the big one: being on the far side of the Moon will get you away from the Earth’s radiation, but not the Sun’s. Anywhere on the Moon, except a few deep craters around the poles, gets the same amount of sunlight. Any optics sensitive enough to do what’s necessary will get burned out by this much light, and would need a sunshield. Therefore, the telescope will be useless or severely hindered for ~14 out of ~28 days.
IMHO, a better idea would be a space telescope in a Lagrange/libration point, always in the same spot related to the Sun and Earth. That way, you block the Sun and Earth with one damn big sunshield (tennis court size). This happens to be the basic idea behind the Next Generation Space Telescope. 
A couple quick points:
Callisto - nasty radiation and an asteroir belt in between
Mars - I haven’t read the A. Clarke book with the 1-10% more fuel figure, but I’d be willing to bet that’s for the same size vessel and a really slllloooooow trip. The trip to the Moon And Back takes about 10 days. Mars and back would take AT LEAST 18 months. Longer trip, more supplies. More supplies, more mass. More mass, more fuel. More fuel, more mass. More mass, more fuel…
Hope that didn’t sound too testy, just wanted to be thorough!
I believe we should go back to the moon because of the technology - if we knew what we would invent/discover, we wouldn’t have to go. Also, it can be a proving ground for technology and planning we’d need to go to Mars.
If you’re interested in the Apollo era, I heartily recommend A Man on the Moon by Andrew Chaikin, or the miniseries From the Earth to the Moon.