Yeah you should be able to invest as much as you want - as long as it is your own cash/sponsors money etc. it doesn't matter (to a degree) where it comes from as long as it is
cash in the clubs bank they can spend with no repayment required - and the money is fully traceable to a legal source.
No problem with a "loss limiting" rules to stop people spending money they don't have but to prevent clubs spending money they have in the bank/found down the back of the sofa/whatever is a madness.
It's like being in the club and not being allowed to by more beverages even though you've got the cash or your mate is buying because Chippy's in there and doesn't want to get another round in (or so I hear).