Force install Mavericks or newer on a A1181 In short, can it be done? and besides not getting updates whats the worst that can happen?

Its a 2006 model with coreduo
Yes it can be done. You would need the MLPostFactor that could also install Mountain Lion. But in Fact it is very unlikely, that this is gonna work out. The Intel GMA950 is not a 64Bit Graphics Chip and has only 64MB of VRAM.

So you would get Glitches and poor (veryp poor) graphics performance.
Even with the 2.4Ghz 2007 MacBook (Black Edition) with full RAM equipped, you won't have fun with it. It was unusable in Lion already.

The worst that can happen is having your MacBook in an unusable condition.