You have retired military in the family so let me offer my 2 cents opinion in honor of their service.
I just bought a PVB contract (Poly) resale buy - not direct.
So let's start with 'option 3'. As far as direct vs resale, clearly I favor resale. The difference in cost is HUGE, and while a blue card is nice, in most cases you are talking about a tremendous difference in buy in price for this perk. I can't say what's right for you but for me, I wanted the points - as many as cheaply as possible. So let's use a quick back of the envelope example:
If it cost $235 a point direct at PVB vs say $150 a point for resale at PVB (to be conservative), it means you are saving $85 a point. This means on say a 150 point PVB contract resale it could save you appx $12,750 dollars. Enough said. I like blue cards and YMMV, but personally? I'll take the $12,750 dollars savings for resale, Alex.
As far as RIV (Riviera) vs PVB, I love the monorail area in general, and it is no longer just a rumor, but a fact that they are building a bridge that will enable ALL monorail
DVC owners now including GFV and PVB to walk to the MK. I do like the skyliner, but at RIV it's going to be only 2 options: skyliner or bus to 2 parks (EPCOT and HS). PVB on the other hand, will give you 4 options (walking, monorail, bus, boat) to MK & 2 (monorail or bus) to EPCOT.
When you mention resale value is uncertain at RIV you are correct, but actually I think it's even worse than that. The idea that any buyer of a RIV resale contract will foregoe a 7 month option at any other resort is probably going to be a huge disadvantage for resale prices at RIV any way you slice it. No matter how much you love RIV, if you plan on going to WDW every year like the rest of us DVC addicts, the idea of never being able to stay at any resort besides for RIV resale buyers is a huge downside. Imagine never being able to stay at a Monorail resort (or any other DVC resort) at 7 months for as long as you have the contract year after year? This is something that would make a resale purchase at RIV for me such a huge disadvantage it would severely effect the price I personally would be willing to pay. Want to keep RIV forever & NEVER sell? Fine it won't matter because as an original blue card owner you still have the 7 month privilege. However if you ever plan to sell your RR you need to bear this in mind when you negotiate with a resale buyer IMO. I know people are complaining about this resale rule and HOPE that the rules will change, but 'hoping' they will change a rule that you are agreeing to from the start and is crystal clear should not in my opinion, be a basis for purchase. Right now this is the rule you are 'signing up for' when you buy at RIV so if you buy and assume they may somehow 'change the rule later' you take a gamble on the contract.
You also mention the costly price of the buy in. However I think it is worth remembering that over 20, 30 or more years of ownership, the MAINTENANCE FEE cost is one of the most overlooked, and significant costs of ownership, and can eventually become more significant than the initial buy in price. While it's true RIV is even newer than PVB with 4 extra years; PVB is not only one of the newest (and thus has a very late expiration date of 2066), but it also has the 4th lowest MF's at WDW - currently under $7 a point. MF's are one of the most overlooked costs at DVC from a financial perspective IMO.
Wherever you decide to buy and resale or direct, good luck and much thanks to your parents for their service!