For a 2 BR I prefer GV over GC because I think the top weeks trade slightly better and it has the Thursday checkin options, esp for those booking more than 1 week at 13 months out (or might in the future). Ultimately it depends on how you'll use it and how flexible you are. If the lockoff doesn't appeal to you and you always need a 2 BR that might be difficult to get some of the lower level resorts without lockoff's might be perfect. I want to control costs, have options and always be trading up but have a real chance of success. For a 3 BR it's likely a wash if the Thursday check in has any advantage and GC might be a little better due to the fact the 3 BR trades as a 2Br & 1 BR rather than a studio.
HI and Aruba will rent well but the up front costs and fees will be more than the upgrade fees. Personally I would decide whether I wanted to use and rent or use and exchange and not try to split the difference between the 2. One of the best high end trader for a 2 BR at reasonable fees is Grande Ocean Gold but you've got to be proactive to get the best weeks. Ocean Pointe Gold also comes to mind and is a lockoff.
My personal view is bad idea if it's for exchange and rental but could be good if you'll actually use it much of the time.
If you'll use it the majority of the time it's a reasonable purchase IMO, your OP suggested renting & trading. Of course view type has no bearing on trading but does on rental and usage. You could book 2 completely different weeks or consecutive weeks and you could do any combination of personal usage, rental or exchanging you wanted. What you can't do is reserve at 13 months out unless you have another week to combine to do so but I doubt you'll have much issue unless you want the 2 weeks around 7/4.
I think Redweek is a very good example of a free market exchange of both sales and rentals. There is enough volume and exposure that it seems a fair indication of market values. They also provide some analytics that make getting a visual representation of pricing easy.
I don't have specific examples for this exact situation but I have traded lessor properties and lower demand weeks for higher rated and higher demand resorts through II. RCI is a little different in that they essentially monetize the trade power and provide ways to upgrade but often at a cost to do so. Personally I've not been impressed with direct trade options as it seems to specialized, too difficult to find a match and that even if you find a situation where both sides are willing to consider it, the chances of both sides being happy with the terms are minimal at best. It's far easier to trade through a formal exchange company or rent out then rent what you want rather than trying to find a needle in a haystack. Realistically I'm not thinking it'd be easy to find someone who wants to trade a 1 BR Platinum for a 2 BR gold but it's not a major stretch either. Through II done correctly I'd say it's very possible to do so, both directions.