OK. Let me try to answer some of these, based on my experience only.
1) I am an intel officer, and have never heard of SWO-Intel. SWO/IP yes. SWO/Intel, no. Being Intel is a specific designator of its own and has no specific tie with the SWO community, or the aviation or EOD community, or whatever, although you may work with all of them.
2) I have a friend who did lat-transfer out of the SWO community and become an intel officer. He did well as a SWO and recieved his pin, although he didn't like the community. He was one of a select group who was accepted to transfer after his first three year orders. It was not a given that he would get this lat-transfer.
3) I know one squadron AI who speaks Arabic fluently and one who speaks Urdu. Neither one of those people are working in jobs that have anything to do with language. Is that messed up and wrong and an oversight on the part of the Navy? Possibly. But, as a first-tour intel-O, you will not be in a language-type job. They do, however, look for people with liberal arts and language type backgrounds to come into the community, probably much more so than other Navy communities.
4) It is possible to be commissioned as a part of the STA-21 Intel-O program from NROTC if you are a prior IS. Otherwise, there are 2-3 people a year who get it due to being broken or some other detailing oddity. I went through NROTC, but I am a flight attrite, and no one else in my 4 years there ended up going restricted line - except nurses, which is a seperate program.
As far as changing your BDCP contract from SWO, I have no idea how hard that will be. Just know if you are commissioned as a SWO, it won't be a guaranteed switch over to the dark side - you will have to deploy and get the pin.