yes you can stack the adapters and do that. 

Not had any problems with mine at all. Great tripod. 

This adapter fits the Panasonic G85 perfectly. If your lens is a Nikon G lens, then you should have no problems. The version of this adapter I have is M43 (Micro 4/3rd) to M42 lens. Hope this helps. 

Yes and no. Using motion detection it doesn't work through a window. However.... using the timer inside it you can record through a window using it. How? Set the timer to record 4 minutes every 5 minutes for 1-5 hours or whatever time you need it to record for. This is what I do- just make sure you have a SD card with enough memory for the videos- I use a 32 GB SD card, I use it though a window as a security camera for my car....I live in an apartment so I can't hard wire anything and this works great for what it is. 

yes, i had no problems with infinity focus with this adapter. the only FD mount lens i use anymore with my sony is a vivitar 20mm, and i pretty much only shoot infinity focus with it.