What's the model of your SpeedTouch?
SpeedTouch 9B5DAC

Have you only had connection problems since updating to 4.16.2 or did you have the same problem with earlier versions? Limewire used to be able to connect, however I do not remember when it did not connect properly, sorry.

Have you been through this thread (I guess you have, since you said that you'd tried all correction methods)?
If LW Will Not Connect Yes but I went through it a second time, just now, to be sure and after restarting my computer the problem still exists.

When you deleted LW's preferences folder & replaced the gnutella.net file, did you make sure that LW was completely closed first (check in Task Manager)? Did you also look for a preferences folder in the old location (.limewire)? Did you restart your computer afterwards? Yes in all cases above

When you tried other Java versions, did you make sure to remove any versions currently installed on your computer, before installing another version? Yes I did

Have you tried port forwarding for your router?
Could you please explain how I might do this...