I have profound hearing loss and the Naida V50 with the UP RIC sounds great but can be too powerful sometimes. Can an Audeo B70-R work for me as well with the UP RIC?

I believe these are important questions addressed between you and your audiologist.  There are many variables that make decisions like this such as your type/degree/configuration of your hearing loss, your sensitivity to loudness, your previous amplification use, etc....I would recommend you discuss this with an experienced, trusted audiology professional to help guide you as you make important decisions for your best hearing.   It is true that some individuals perceive RIC's as sharper or more harsh as compared to more traditional behind-the-ear (BTE) devices with a traditional earmold so if you have used a traditional BTE in the past, sometimes it's common for RIC's to be perceived differently.  You should also make sure you have an assessment period with whatever product you jointly agree on so you can make sure you are fully satisfied within what is realistic for your underlying hearing ability.  

Most likely yes.  The UP Receiver is rated to 136/72 on an ear simulator for the B90/70/50-R.  If you are having success with your Naida, you should be able to swap out the hearing aid body for an Audeo.  Achieving similar power shouldn't be a problem, your audiologist should be able to knock this out for you relatively easily. 

To be honest, a couple of factors need to be taken into account. What is the exact morphology of your loss? Profound is a range, so looking at what we are dealing with in the scope of your loss is important. Also at this level, do you have any recruitment? The short answer is maybe? The Naida has a much more powerful output (132/65) where the Audeo B is a 111/46. If your loss is such that it requires the power of the UP, then you might only need an adjustment.If you have recruitment, then your fitting range is reduced and your audiologist may have to do some work on your programming. With the B70-R you are getting a much more advanced chipset, but maybe not enough power to give you the audibility you desire.