YMMV This is what works for our travel patterns and budget. You may have different locations, budgets and quality preferences.
Would you go back and change your "home" location?
We bought retail 10 years ago and regretted that. We bought resale and have benefited greatly. Currently have 5.5 weeks across HGVC and Vistana because you cannot have just one. 
We sold 1 resale VOI to adjust our portfolio to a better one.
Would you buy more/less points?
I am pretty happy with our current mix. Currently playing with Interval International (II) and Vistana SO points that were more recently acquired and may sell a Vistana that we use due to high MF because we are tiring of the location, it is too expensive to trade, and we are on the verge of having too many.
Would you use RCI more/less often?
We have gotten a few gems e.g. Four Seasons Vilamoura Portugal but mostly trade in-system points, DEX and II. RCI has gotten increasingly expensive with resort fees tacked on making in-system trades a better value for the quality. RCI has a lot 3 star resorts including Wyndham vs. HGVC 4 star. Why trade your Cadillac for a VW Golf?
Would you sign up for the Hilton credit cards to get more HH points?
Yes. And we pay MF for these. Great for augmenting trips with extra nights.
Would you attend more/less sales presentations to try and get more free points in your HH account?
Fewer. We were using these to get discounted stays but now realized that with our resale timeshares that trade in II and DEX that we can get better value exchanging and then take HHonors or other offers as they arise at the resort. Pretty high bar for us these days.
Would you use a different company (not use Hilton) for your TS travels?
We own both HGVC deeds and Vistana with SO points and II trading. These systems complement each other with different locations. II trading is valuable to access Marriott, Hyatt Disney properties. SO points is best for in-system Westin and Sheraton trades.
What would be your ideal starter point/location deal?
HGVC Vegas or Craigendarroch Lodges Scotland for HGVC deeds
We also own NYC because we like to go there so would pickup a resale there.
Outside HGVC to complement:
(free) Sheraton Desert Oasis to trade in II for MVC and Vistana if you can vacation for a week at a time. IMHO II Is better than RCI because you can access Marriotts and some Hyatt and Disney.
Westin Kierland (mandatory SO points) for use in the Vistana system (costs money)
If you want to discuss any of these options in detail, please PM me.