Will using dry lube and wet lube together give you better protection/performance than from using just one of them? I think the only way to use them together is to put on dry lube first and then wet lube.
Will the wet lube hold? Will applying both give you the best that each has to offer?

Update
Just found this video on YouTube. It teaches you three techniques to clean your chain. If you forward to timecode 8:20 of the video. He mentions that you can put on Finish Line's Dry Teflon Lube and later you can put another lube on top of it:

                
            

Just wondering if this is ok.

Update
Just bought some Finish Line products to do some chain maintenance. On the back of the Finish Line product pamphlet they have a list called "Pro Team Mechanic Tips". Two of the items on the list contain techniques that use two different lubes/greases on the same chain...I've included them below...


In extremely wet conditions, some mechanics will lube the chain with WET lube, then apply a top coating of Teflon Grease to the chain.
In semi-wet conditions, some will apply DRY Lube to the chain as a base coat, and then a top coat of WET lube.


So, I think based on this list and the video link I found above.  Applying both lubes is an acceptable technique.
I don't think so - they are designed to be used individually, and for a specific purpose.

Like I answered to a previous question, the Wet / Dry naming of the product is a hint as to what conditions the product is designed for.

Wet lube is typically more like motor or sewing machine oil, and is designed to coat the chain and protect it in wet conditions. This will pick up dirt and gunk, but it will be mostly kept on the surface and will help keep water and other corrosive substances out of the links.

Dry lube is usually a teflon lube in an evaporating or wax base, so the teflon particles stay in the links without a lot of wet "gunk" left on the chain to pick up sand, dust, grime, etc. and is great for dry, dusty conditions.