I find the biggest problem with the spacewalk, as we have it, to be that it's not properly framed as being the suicide mission that it really should have seemed to be. Spock should have no reason to think that his log will ever be recovered, because after he's burned up all his fuel, he discards his thruster pack.
Why the heck couldn't they have made it a 40% fuel burn???? Heck, if they had done that, Spock could have set the autopilot to return him to the ship before making the first burn, just to better make sure that his log makes it out of the orifice. That way, we're also not wondering why V'Ger would bother to spit him back out, especially if the mind meld didn't discernibly affect V'Ger otherwise.
No doubt production time crunch played a role in bringing on the nonsense.
I seriously doubt that Spock traveled far enough that he was out of range of the Enterprise's transporter. Geosynchronous orbit around Earth is 26,199 miles (42,164 kilometers). Do you really think Spock traveled more than 26,000 miles away from the Enterprise during his short space walk into V'ger's next chamber? Even if Spock was out of range of the Enterprise's transporter then couldn't the Enterprise use its tractor beam to open the orifice of the next chamber so that a shuttlecraft could travel through it and rescue Spock?
Navigator NCC-2120 USS Entente
Force the orifice open with a tractor beam? Not likely.
Scans couldn't penetrate it, and the whole reason Spock went on the spacewalk in the first place was to get information about the inner chamber. I would assume that communications were blocked too. In that case, there would be no way to get a lock on Spock to beam him out. I doubt the transporters could penetrate either, for that matter.
Phasers and photons, maybe, to blast a hole in? Sure, if Kirk would like to risk getting the Enterprise
digitized, assuming they're even effective at all.
Yes, Spock would probably stay in beaming range, for whatever that would be worth. It would be a case of "so close and yet so far".