This... would work well. It'd probably get rid of those enemy tanks that park under the MCC too...

Still, this is a GOOD IDEA, but if CCP implements it we still need some non-idiotic spawn placement. As the OP notes, the only reason to do such with this would be to actually win the game for the team, which some people actually are interested in... and I'm tired of landing on enemy tanks when diving from the MCC.

I like the idea but it would not change that tank behavior. The tank would be in their normal zone and would be free to remain there. The problem you state can only be fixed by proper placement of the MCC and the Yellow Zone/Red Zone/Green Zone/That other Zone definitions. It could indeed be solved with no other changes than proper level design currently.

The biggest confusion today is there are two Red Zones and some of us do not seem to recognize that. Others do but detest vehemently that their victims having any safe harbor what so ever. You know, those fun loving murderous savages that CCP wants to market this game to.

Enjoy.

My problem from not getting any reward from shooting people in yellow areas is this: They can shoot you and kill you. If you kill someone who poses a very real threat, you should get rewarded for killing them. I don't like the counter-idea of having to wait for someone to fire at you before they become an eligible reward target. That's asking to be killed.

If one team loses all points, the game should rapidly end so as to make the concept of fighting in the redzone a non-issue. Being camped isn't fun, camping an enemy team isn't fun. If the game is so lopsided that one team gets trounced, a Battlefield-style depletion should commence so as to let everyone get out of the boring game and get into a new one which is hopefully better matched.

I do appreciate the "yellow zone" concept. I really do - it would fix our issues with current map design, or at least discourage abusing them.
However, anyone who's played the earlier stages - back before the E3 build - will know how this archetype of maps weren't really intended for this kind of redzone usage - which is allowing the problem. They were originally designed to be the final objective zone of a multi-stage, MAG-esque battle.
The old design took different maps, and puzzle-pieced them together, with the redzones hidden well enough to avoid sniping to or from those zones. Say you placed the map "Biomass" at the end, then it would be set up somwhat like this:

{un-named attacker staging area}----------->[Crater Lake]--------->{Biomass - defender zone}

For the first stage, defenders got to use an entire base as a staging area, and it was completely hidden from the attackers by the first map stage. Once the first stage was lost, attackers moved up to the end of the first stage, while still having their fallback spawns hidden from fire.
Maybe it was the mode, maybe it was that Crater lake was one of the best tactical maps CCP came up with. Either way, returning to one of those elements would actually help our red-zone problem. Sounds a little weird, but it would indeed help.