Maximized awaken: 18 int, wis, cha (not sure if this is RAW but who cares, you're an ooze!).
What's the point buy? How would that work with limited stats? Anyway, put an 18 in con and the rest in Str. Dump dex, it cannot go below 1 after all.
Gelatinous cube has 4 HD, I assume you houseruled 3 LA. Ouch. You could buy it back at levels 13, 19, and 22.
Anyway, with 34 Con, I'd go for some Con synergy. Ideally something like cube 4/stoneblessed 3/deepwarden 2/fotf 1 to increase your AC from 4 to 33.
Meeting skills and feat requirements will probably be complicated, perhaps dip some ranger. The 18 int can help.
Oozes probably cannot wear much equipment, have you considered VoP? Nymph's Kiss would probably help too.
Strategy: increase con skyhigh, use cube's natural attacks and pump paralysis.
Feats: Extended reach, Ability Focus, Rapidstrike (ouch, needs 9 dex)...
Ask your DM if ranks in Hide/Move Silently can help improve your Transparent (Ex) quality.
I am not skilled with ToB, but can this help? Insightful Strike - Tome of Battle p62 3.5 - Concentration check instead of damage roll