Advice on wood rejuvenation and preservation

I am restoring my weathered greenhouse made of the old growth redwood and it's located in the west coast of USA. It will be used as outdoor dining patio. As you can see on the photos - I am having an issue that the post does not allow pdf.

Img - exterior worse one --> one of the worse shape of the wood

Image - interior with moss and possible mildew 

Image - interior better shape

Interior is always protected from weather due to the glass which is part of the greenhouse

Ask:

1.  can I use the Restore-A-Deck: cleaner and brightener products and no need for sanding

2.  For stain - shall I use the Restore-A-Desk: Natural, Semi-Transparent stain

Shall I move away from the oil-based products?

Please feel free to provide advise on the most effective way to restore and preserve this redwood.