Depends on how long you plan to stay in the unit. If it's just going to be a stop-over and you plan to upgrade in the next 5 years or something, then I'd say no need to do anything and just roll with whatever problems that come later.

If you plan to stay there long/forever, then it's better to get some work on the plumbing done. It it's an old apartment, maybe they used steel pipes (?) that may rust and cause low water pressure issues. It's good to tackle these problems now (maybe install water pump as well) because fixing them later while you live in the unit is going to be a nightmare.

I'd say power points are less of a concern unless you think you don't have enough. Again, addressing this issue now is better than later.

Concrete slabs can break no problem, just pay your contractor more and check with management how long can they do their work because it's going to be quite noisy so there may be restrictions.

As for your budget, should be more than enough to address the plumbing.