On the topic of PSR, the psr penalty is something you can offset, by paying BV. You also get a discount, like from small cockpits, cause of the piloting penalty, so it's not like you don't get something for it if you stay at 5 base piloting.
A BV manipulation method that works well enough for quick pick-up games and doesn't work at all for campaigns. One does not simply pull an expert Battlemech pilot out of your hat so you can pilot small cockpit or torso mounted battlemechs, or hardened armor battlemech or such, for free- at least that's certainly not how any of our campaigns did it.
No ejection is not a thing. Some people may play campaigns, and may care about how their pilot takes damage. But a headshot kills a pilot, and losing all your torso structure kills a pilot. But its much harder to kill a pilot with 15 damage when you take a torso cockpit. As for ammo, case exists to offset ammo explosions going to the center.
No, Torso Cockpits
cannot eject. Tac Ops is very clear about that.
The center torso takes hits 7x as often as the head from the front and rear. Even on Battlemechs with the heaviest armor like an Atlas, the Battlemech is more likely to suffer crippling engine damage, gyro damage, or even structural collapse, before the head is decapitated. The likelihood also increases when taking into account damage transfer.
Torso cockpit 'mechs are also still debilitated when their heads get lopped off, since losing those head sensors effectively blinds the 'mechs and smack a massive +4 penalty on essentially every roll, both to-hit and PSR: You're mission-killed, which will translate to being actually killed (or at least captured) if you lose the fight (and probably even if you win it because you're flailing around like a headless chicken), which you probably will since you just had a bad stroke of luck getting decapitated. Torso cockpits trade dying instantly on a headcap* to instead be
probably dying due to a headcap a minute later and definitely dying on CT loss, plus extra vulnerability from heat in certain scenarios and being more difficult to pilot. And increased tonnage.
*Optional TacOps rules apply, results may vary
A fun thing--due to the damage transfer rules coming out before torso cockpits were a thing, if your ammo in your head gets hit or you take a big shot like an ac20, all the excess damage just goes away. So while you pay +1 ton for a torso cockpit, you save .5 tons on case. The head ammo bin is ideal on torso mechs.
A novel approach, but one that has its own limitations. Such a 'Mech could only ever host 4 tons of explosive ammo, and plenty of weapon systems are sufficiently ammo hogs that you could easily need more than that.
There is nothing you can take to survive a headshot without torso mounted cockpits, and the penalty can be offset and the advantage is unobtainable any other way, including no damage transfer. For every osteon you lost to breakdancing, other mechs died to headshots, and those mechs didnt have an option to pay BV to avoid it.
For ERPPCs: Reflective armor, Blue Shield
For Gauss/AC20: Ballistic-Reinforced Armor, Hardened Armor
In General: Modular Armor attached to the head (thought it was restricted from that location but upon review apparently not?)
15-pointers with quirks: Ferro-Lamellor + Armored Cowl quirk
All of these have their own quirks and caveats of their own, but they're not unique in that regards: The torso cockpit's fine print is just painful.
It isn't a theoretical. I've used Torso Cockpit battlemechs as OpFors in campaigns before; they consistently took a
much higher pilot death % per killed Battlemech than other models using conventional cockpits, with the situation being especially dire for lights and mediums where the torso cockpit was an active hinderance. Through all the torso cockpit 'mechs used I've only ever seen two exceptions: One area was superheavies where torso cockpits don't exist anyways, and the other was this very unconventional 100-ton quad that acted more as a zombie ECM + sensor platform than as a conventional Battlemech, and that one couldn't exist in canon anyway due to its eclectic equipment loadout.
Also, just since the cockpit is a piece of Tac Ops equipment it seems fair to me that we take a look at its optional rules as well. "Skin-of-teeth Ejection" allows Mechwarriors to eject on decapitating strikes and potentially survive one.