Regarding the 163 and HQ.
First, I think the idea of HQ controlling radar for the entire country is absurd at best. HQ should control messages of a base being attacked or dar bars more than four sectors away. In other words, if HQ is down, you should only see darbars and dot dar within a four sector radius. Further, you shouldn't get base under attack messages or see flashing bases unless they are within the same four sector radius. And I'm not sure HQ being down shouldn't affect the country channel in the same manner.
The fact that HQ affects your SA over the entire area of your country in that manner should be enough incentive to protect it. That would also eliminate the need for a country down to a very few bases to worry about protecting HQ, and keep them from being denied radar for SA. And it would prevent the stupidity of porking HQ just to annoy people, by taking radar down for the whole country.
It would leave some incentive to hit HQ as part of an overall organized attack.
The 163 is, I suppose, nice to have to protect HQ. But if HQ is that important, it should be better protected. An incentive would be a (relatively) large reward in perks, points, or rank for killing an enemy in the same sector as your HQ. That would encourage people to patrol some near HQ in something that would be an effective bomber killer. Then just leave the perk system in place with inflated perk costs due to the numerical imbalance, and allow perk planes to be flown at the inflated costs.
Or, as an added part of the "new system", leave them disabled, but allow lower ENY planes to be launched from bases within a sector of HQ. This would allow planes like the P-51D and the P-38L, among others, with sufficient fuel to reach high altitudes and patrol with long endurance, to be used to protect HQ. But it would cut way down on their usage as attack planes. And it would effectively prevent other planes with low ENY values from being launched from those bases to make offensive moves. You could allow the planes to carry drop tanks only, and no external ordinance, to prevent their use as anything other than a fighter to defend HQ.