[dbrueck]

Two things to consider: it seems reasonable for any organization - including a non-profit - to save some for a rainy day, and anything that doesn't get used immediately and doesn't get invested loses value just by sitting there (due to inflation).

IMO neither of those is enough to warrant a blanket "sure, why not?" answer to your first question and for there not to be any restrictions at all, but off the cuff it doesn't seem terrible.

As to your 2nd question: assuming you live in the U.S., it follows the laws of diminishing returns. It might be worth it to sit down with a non-sleazy tax adviser one time (and again each time you have a major life event) to make sure you're not missing anything big and/or easy, but pursuing every possible honest deduction is exhausting and time-consuming and so you eventually reach a point where chasing that next deduction is not worth your time.