With so much spare space I'm a bit surprised that a couple of gig of vm would cause so many problems. Plus the LW versions since about 4.2 I think use less physical ram. Mine's using 138 mb & 1.7 GB vm at present. But I have a lot of incompletes, about 3k shared. Likewise I only use Resume in circumstances where it's been downlding earlier. Though I often try other techniques 1st such as stopping & reselecting from S. results if there was any search.

Do you run as an ultrapeer. Under those circumstances it would be best not to. Disable UP cap. under Speed in LW's prefs.

A couple of other things to reduce VM, set your downlds to Auto-clear & delete search results that are a few hours old.

Delete any old incomplete's that are 0% from both incomplete & downld window.
Perhaps you should reduce no. of shared files also if you have many k's of them.