Have you tried this part?

If with that it should still go into waiting to run, I'd try:
<ram_max_used_busy_pct>70.000000</ram_max_used_busy_pct>
<ram_max_used_idle_pct>70.000000</ram_max_used_idle_pct>

And than set in your client_state.xml (exit BOINC first):
<user_run_request>1</user_run_request>

You have there a 2 probably right now.

Also post the log, when BOINC suspends the task.

It also might be helpful to use <cpu_sched>, <cpu_sched_debug> and <mem_usage_debug> in cc_config, so we can better see in the log what's going on there.

What is the size of the pagefile/partition (whatever that is called in Linux)?

So far it's gone the entire weekend with no hangups. I'll keep monitoring and apply your suggesting is it hangs.

Well as a final warp-up I am processing for about 4-5 days without a termination. At this point I can live with that. I want to thank everyone on this list for your suggestions and help.