Yes, people had/have trouble with UrukDroid and WPA and WEP; it has been discussed a lot at the dedicated Uruk thread at xda-developers http://forum.xda-developers.com/showthread.php?t=895599
Responsiveness in a GUI isn't all about clock speed. More important is the amount of RAM available, memory caching, the kernel scheduler and the speed of disk reads and writes. The brick wall in the case of Archos gen8 is the available RAM and it is
a brick wall. There's nothing you can do about that and everything else is much less important. Clock speed isn't much of a factor. If you look at your Archos' /system/etc/fstab* files you can see that the filesystems containing the OS are ext2 and ext3 mounted with noatime. Those are good options for a well performing file system that avoids unneccessary disk writes. Your personal files by default are probably on vfat (FAT32) which for all its limitations is still a fast file system. Switching to ext4 offers journaling so is safer but doesn't improve performance (in fact it's almost always going to be slower) unless you move around a lot of very large files and need to avoid fragmentation.
What you'll get from overclocking is some very marginal performance gains in some areas but a lot of instability and hugely reduced battery life. I'd suggest a better approach is to forget overclocking and instead try out a CPU frequency scaler change in conjunction with a different kernel scheduler. I don't know what the default scheduler is in Uruk, but in Archos it's anticipatory. Using a free app like No-frills CPU Control you can set it to deadline and set the max available clock speed to 1000. You could also try a different governor such as performance instead of on-demand. Maxing the top range for frequency scaling and setting a performance governor will negatively impact battery life but nothing like as much as overclocking. It also shouldn't introduce instability or mess with sleep states.
I recall that when I used Uruk whatever settings I made the CPU basically never ran at it's lower scale of 300 MHz and it ran through power at an alarming rate, so now I use Chrulri's root which is like stock firmware with benefits. If you try Chrulri's then get the "temp" version and avoid the r+w version which has appalling performance due to the way it uses a mounted compressed filesystem in place of the Archos /system. Despite the name the temp version does allow you to write permanent changes to /data and run most root apps without issue.