Staining Covered Porch recently built

I recently built, and still finishing, a covered porch that extends off the back of my house. I was going to stain right away, but I started reading and learning more about exterior staining and found your site to be very helpful. I'm wondering if the techniques used to prep/stain a deck applies to the porch wood as well, specifically the interior walls and rafters. The outside portion I'm assuming is treated the same since its exposed more to sun and rain. 90% of my surfaces will be vertical or non contacted.

I will be screening this enclosure in to protect my family from mosquitoes. The dilemma I'm running in to is that I want to screen asap due to the mosquitoes already being out and biting like crazy. But to minimize work, I would like to stain the porch prior to putting in the screen tracks. The enclosure has been up for a month now "weathering." I have a handheld moisture meter to check the moisture content. Any idea on a particular number to aim for before applying stain? My plan is to go with Arm&C semi transparent.

For my rafters, I will be leaving them exposed, and laying a T&G cedar between the rafters for the ceiling. Do I still need to prep the rafters with RAD before staining them? Seems to be difficult to do now as the peak of my ceiling is about 14 ft up, and with a lot of spraying and water rinse going inside the porch area. Is it necessary to prep the rafters the same as I would a deck floor? I need to stain the rafters before installing the ceiling, so I'm at a stand still until the rafters are done. This question would also transfer over the interior pony wall covering which will be T&G cedar as well. 

My real issue here is until I can start staining the enclosure, I cannot continue to work on the finishing touches. The screen itself is a huge thing to get up asap due to the bugs already biting. So I'm trying to patiently wait as much as I can but its heartbreaking not being able to enjoy the fruits of my labor in the evenings yet. While I'm not looking for a shortcut/quick fix, I'm asking for some advice for staining and finishing the wood so I can continue to built and finish the porch completely. I've attached some photos for reference.