For instance, infinite space might be a hard concept to wrap your head around, but think of how easily it could be programmed?
'Infinite space' as in stars, planets, nebulae, etc, or just simple empty space?
The second one is significantly easier to do - and in that case infinity would also be pointless. If it is indeed empty, there is no real movement (nothing to compare your position to), so your space only needs to stretch beyond the range of visibility
A filled space, on the other hand, would need lots more programming, not to mention the hardware requirement of running the simulation - especially as you need to expand the space as the viewer explores more of it
I was also thinking about the 'rock so heavy he can't lift it' from a programming standpoint.
When you are the one who makes the rules, the only limitation is the one you place on yourself.
So it would be possible to create/program a 'rock that you cannot lift', simply by flagging the rock as 'unliftable'
(Also from a christian point: can God create a rock big enough that he cannot lift it?
The answer would be: No, as he does not do pointless things)