Army Cache Boost my first Insane, AV my second. I would do it that way again.

Insane AV means money is no object on any level. I like it, if overkill some levels the peace of mind is worth it to me.

My active slot is always occupied by Legendary Time Warp. Time Warp helps everything--digs and hospital upgrades are just the most obvious benefits.

Mercenary Discount, Hospital Boost, and Cache Boost are the only other cards I use every time I play. A Legendary Quad or Triple Strike is nice to have on certain levels, and a Supercharge Army Camp is sometimes worth a slot if I want a fast start to a level. The generic Cache Boost at Legendary plays very nicely with an Insane Army Cache Boost. When attacking add Hospital Boost and you have the ideal use of slots.

Most of the passives are not really worth all that much in the scheme of things. BMB and TMB are irrelevant with Insane AV. ACampB is small stuff, compared to what Caches and Joint Strike and Hospitals saves/earns in troops. Do not upgrade Army Camp Boost beyond Epic ever.