Wet Gate is a process. In simplitisc terms the film goes through a chamber filled with liquid, this minimises some scratches at the expense of a slight loss of contrast. The gate is quite literally 'wet'.

You can get similar results by using multiple passes of filmguard (it takes 4 or 5) to work as a pseudo wetgate, the filmguard liquid coats the film and does a similar job. A true wetgate is better though.

I am currently saving up for a real wetgate for my system, it is about $500, but is worth it. Currently I use the filmguard method if a 'wetgate' transfer is required.

As for log vs lin, 8bit vs 10bit, it is a complicated issue, but this intro from QVO isn't a bad place to start.

http://www.qvolabs.com/Digital_Images_ColorSpace_Log_vs_Linear.html