Sounds like some good and realistic goals you have set for yourself! I think by the time you're making it consistently to stage 7 you'll be able to easily score a letter with the Bat though.
Some tips on Mad Ball (already mentioned in the thread, but distilled to a point);
Always wait 5 cycles unless you're very confident in all aspects of the boss (possible to utilize fragment invincibility earlier to kill the outer ring before the fifth cycle).
Ideally you want the boss to move as far down on the screen as possible but for safety's sake; suicide as soon as you see the boss moving downwards when you've waited five cycles. preferably as early in the attack as possible.
Wait to deploy the bomb until when you're hovering over the boss.
If you've timed it correctly you should be able to bomb a second time (for the inner rings) as soon as you've respawned from the suicide and reach at least 3 mil for the third and final suicide.
Junky Monkey is pretty tough but the first two forms should be easy if you've managed to keep homing formation throughout the stage.
Otherwise; on his first static form focus on destroying all of the left side turrets asap and then stick to the mid-right side of the screen while firing at the core and and dodging his bullets.
This way most of the turrets on the right side will be off screen.
For the second static form; kill the two turrets on the left as soon as the form activates and immediately move to the right to kill the other two.
You should be able to macro dodge his big spread with the missiles if your timing and positioning is correct but be prepared for some micro dodging through the spreads. Don't be afraid to bomb if things get out of hand.
Watch out for audio cues for the fast spread. Safe areas are in the middle and a quarter of the way to the side of the screen on either side.
For the final form; first destroy all of his turrets ASAP so he'll pull out both of his arms.
During this form, when you're focusing on milk destroying the arms and turrets he deploys, try to keep yourself about 30% up from the bottom of the screen and about 20 degrees to either side of the core as bullet density seems to be the lowest here in general.
For medals on stage 2; always be mindful of the item drop order. If you know the you've got a medal coming up when you're reaching the blimp you might want to focus on just destroying one medal carrying side of the blimp and killing it ASAP for safety's sake.
Try to kill the big tank ASAP (utilize a small bomb) and again, keep watch on the item drop order as WS ships are slow and you'll need to plan ahead for where the medals will drop in order to reach them.
Either trigger wide formation and stick in the middle to kill all planes and easily grab medals or utilize the option formation button to pick them all off.
I know what you're saying about fatigue.
A cup of something (tea/coffee) helps me keep focus in the beginning at least.
