I already know the CPU priority trick , been running it in low priority since version 1.9

And I still have a good 10MB of memory open .
It's running on a dedicated PC together with an FTP server and I already tried to fish out and disable all unecsery programs .

Besides after I posted this I took a good look at limewire.props and figured it out myself .

I changed the parameter MAX_SHIELDED_CONNECTIONS
And now I can control the maximum leaf connections easily .
Made it 20 instead of the default of 50 and LW is now runing fine .