Since only 2 of the 4 the OP listed that participates in Points.com there probably isn't much point. Webflyer has a calculator for things like Hilton exchange but that won't help with most of these programs anyway.

Some of them do allow charity donations - just look up the programs own website.

QF allows redemption for rental car discounts for as little as 250 miles so that may be an option if you want to burn them.

AA allows redemption for magazines for 600 miles and has other redemption partners as well.

With 4 programs, it won't be hard to look at the options of each one. There is no way of merging them all into one account though.

If you have really small amounts then there may be no point in just not letting them expire.

Out of interest, what is your approx. balance in each account? That would let us suggest usage options more easily.

If you are in the UK then your options are going to be limited I am afraid.