On vehicles: (nice pretto start )
The single most expensive event is that a '41 Tank/Mot Division is made to surrender or is used as a punching bag. The counter is to not use these in combat or in the front line (except the 2 at Pskov - they are needed). I'll even disband up to 20 Tank, the majority of these 20 will be many of those that survive the Lvov pocket and can reach a hex where disband is allowed.
The rest and the MD:s never moves WEST until after converting to TB/ID. I think that movement EAST can be made overland - you'll then likely save 85% of the vehicles in the unit instead of 100% but that's fine and much better than 0. The southernmost 3 (2TD/1MD) can use sea movement to Kerch from Odessa. The 4 or so arriving on the east edge moves 2-3 hexes along the rail line to clear up the entry hexes and then stay put until converted.
Since this removes quite a few units from being available for front line service, it is necessary to make at least some disbands of TD:s to make men available to the infantry, say 100k men (doing the full 20 would give ~150-165k). There are enough TB:s left to make Corps. All TD:s on 'Ready', MD:s can be on 'Refit' to gain mor/exp.
All in all, this should make the per turn 'Vehicles lost in combat' a low 3 figure number once the border pockets are gone. At least until you have to make an exception due to events occurred - if say a large part of SW Front is pocketed, usage of the TD & MD in what has become the reserve to screen Kharkov and/or Stalino to get the factories out is of course sound play.
Air bases are expensive to move OL or by rail if they contain a lot of fuel & ammo. They do have that if they have LB type air units assigned (or had when the turn started). This means that movement of air bases with LB must be planned a turn in advance so that they can be emptied of air units the turn before they are to be moved.
Now, LB have a very long range, so it should not be necessary to move their bases a lot so planning is not such a large effort as it might seem. But they do not have to be moved on turn 1, so don't.
As to the rest, I think it's OK to move them OL without concern for vehicles during turns 1-5, though except for the NW Front ones, I'd rather disband a SAD base instead of moving it.
By turn 6, the number of bases in use should be greatly reduced due to SAD disbands. The Northern Front should give up bases to NW so that NW can disband their SAD as well. It's still OK to move OL - you have to since rail is used for evac.
Most FB have a decent range, so bases can be somewhat to the rear and should therefore not have to be moved every turn.
To sum up vehicle saving regarding air base movement, I allow some break down losses but strive to avoid the avoidable ones.
Supply OP vehicle losses is in direct proportion to how many movement points the supply & fuel points has to be moved by vehicles.
Combat units must be where they must be, so no savings to be had here, apart from the ones from not having to supply & fuel all those fuel dependant TD:s - they are moved OL but to always end up on a rail hex. Another loss not suffered is from tank SU:s since they are not built nor used until the Lend lease have kicked up to the '43 level. I also tend to not have artillery SU in action during '41 except vs. AGN. Saves on ARM as well and I can assign the high exp ones from STAVKA when all SU have been collected there after the first few turns. (I digress, I notice. Back to topic.)
Air bases and their Air HQ:s are always on rail hexes as well, so no SuOP vehicle losses here either. The Army HQ:s must be given a little more flexibility but given a choice, a rail hex is preferred.
The majority of the SuOP losses will occur during the blizzard offensive. This is simply due to that the distance to rail in MP increases (hopefully). There are two things to do that can mitigate your vehicle losses.
I favour a generous number of RR Brigades with an average of 10 per active front. This totals to ~100 and will tie up 300k men which is probably double what is typical, but I want to do all that can be done to repair the rails. Supporting tricks are to first ensure that you have not stacked units in the hexes that are to be repaired - the RR brigades must have room - and to stack 3 high in the hexes that are dead ends or leading east so that the RR:s are not doing unneeded repairs. Defending the western most rails during the final snow offensive is also a good idea, but those hexes are most likely the ones the Germans wants to capture.
Then I avoid blindly shoving everything forward. If a unit is unready due to low TOE this turn, it most likely will not receive enough replacements even further from a rail hex next turn to achieve ready status so it is probably best to leave it or even move it east. This is of course dependant on that there are men & ARM available in the first place, but that is another issue.
Also, during blizzard (& mud) the air bases are moved by rail. There should be ample cap available, and with this routine in place it's more likely that the air bases will end up on a rail hex, which is very important during blizzard. Do look into using air supply during blizzard to have enough ammo in the leading units.