Treating big Glulam beams

[Landlady]

We have big beams running through our house build and I'll need to finish them in spring. Does anyone have experience with conditioning or staining beams like this for indoor and outdoor? As you can see from the photo they will need outside protection but are protected from most elements by the large roof overhangs.

1. Will I need to sand them first?
2. Do they need wood conditioner or can I skip this step?
3. I've picked an outdoor stain (Cabot Cedar). Will this be ok on the indoor portion too or do I need to worry about nasty chemicals?
4. Do I need a polyurethane coat too?

This is a BIG job for me so I'm trying to figure out what is absolutely necessary for reducing future maintenance.

[fishnfool]

I would use boiled linseed oil. Preserves the wood and brings out the natural beauty of the wood grain. No, you probably wouldn't want exterior stain on the inside, very toxic fumes.