[MythX]

Hi, I have a deck that's about 10' up (it's off the master bedroom). It's 10x15', and was built in 2007. It's supported on one side by the house, and on the opposite side by 4 4x4 posts. According to the plans left by the sellers, the posts are stuck in concrete beneath the surface, so the top of each post has twisted. They appear to still be structurally sound, but look horrible. Anyway, since the 4 posts actually block a pretty awesome view I get here, I'd like to replace all 4 with 2 6x6/8x8 posts (one for each corner) and a beam.

My questions:
Is having the posts set in concrete below the surface better than set on a concrete footing above the surface?
What kind of posts should I get to prevent twisting/splitting in the future?
How should the beam be constructed? What material?
If down the road (say 5 years), I want to build a sunroom on top of the deck, how should I handle these posts differently so I'm not redoing effort?
Since there was a permit pulled to install the deck, should I pull a permit for this change to its structure?
Are there other questions I should be asking?

BTW, I live right outside El Paso County, CO (just outside Colorado Springs)

Thanks in advance

 

[carpdad]

For 15' span and the future roof in mind, you probably will need triple 2x12 beam, each 2x must be one piece, you can't join 8', and if you join them, you must have a footing and post under the joint.
Below ground post may resist racking movement but will rot faster. Above ground post will need bracing.
Permit doesn't last that long. It's best if you get the permit within a year of the work.
What youre asking are fairly significant work, and needs details that shouldn't be confirmed in a forum. You need a professional, carpenter or engineer to get the permit.