1. I have not had any experience recruiting or coaching twins on any of my teams (sisters, but not twins), but from the teams we have played against, there have been a few sets. On average, I have heard much more of twins being a package recruiting deal, than being recruited separately. I think it is a cool thing, which smart programs would maximize in recruiting and program marketing/promotions. I believe most coaches are smart enough to be able to 'get two for the price of one'. But, this is something which must be communicated early and often in the recruiting process because the dynamics of scholarships and roster changes is fluid in today's college volleyball.
2. Oh, how I wish your second point could be true. For a number of Olympiads, I have seen great performances in August Olympics and then stared in disbelief as those great performances had no affect upon the collegiate season. This is the 3rd Gold for the women's beach and 2nd silver for the women's indoor teams, but no tangible carryover into promoting/supporting the indoor collegiate game (both May and Walsh were All-American indoor players). All you have to do is the leave the shores of mainland USA to see the popularity of women's volleyball; from Puerto Rico to Brazil and Hawaii to South Korea, women's volleyball enjoys great support.
Volleyball will not explode in popularity, even though logic says it should, because the Powers That Be do not want it to explode. Collegiate athletics is being driven by the Beast of Football; this is a huge change from 10 years ago.
With the feeding of this beast, all Athletic Director and School President logic has gone out the window; football always wants more, and the Adults are afraid not to feed it. What is left of today's Athletic Department Apple Pie is instantly hoarded by Men's Basketball and then Women's Basketball. Athletic Directors are just as aggressive as head coaches about climbing the financial ladder and jumping to new jobs; they do this by their football and basketball teams being successful - I had written an earlier post about Lisa Love being fired as the Athletic Director at Arizona State; her athletic department had won multiple NCAA Championships but unfortunately for her paycheck, the Sun Devil football and basketball teams were marginal.
In summary, the Athletic Departments are pouring so many financial and staffing hours into football, that they have to cut support to other sports - There is no way they can afford to cut support to basketball because of the contract that sport has with televising "March Madness" and the resulting cash grab by the NCAA (which gets nothing from the football bowls) and they can't cut support to women's basketball because of Title 9. I know I am speaking in very broad terms, but these broad terms apply.
Volleyball is on television more because they are being shown on conference networks, which are a new creation. The reason they are being shown on conference networks is that the conferences that are popular enough to have their own networks, also sold off the television rights to their football teams to the major networks. This results in conference networks which are scrambling for content to fill the airtime; this is great for volleyball and soccer. When basketball season comes, there are enough games on the schedule that the conference networks can shift to showing basketball games and football replays.
Sand Volleyball is still TBD. Yes, a number of programs have added sand volleyball but the reality is that many have not and many will not (midwest schools can't really sponsor sand volleyball when it can snow in April). As for scholarships, that is the question.......Because indoor volleyball players can play sand it complicates the financial opportunities. For athletic directors, sand volleyball is the perfect equity addition; they can count more players without having to invest money into the sport (when compared to starting a rowing team, or soccer team, or even a golf team).
I thought Volleyball was primed to jump after the 2008 Olympics (2 beach gold medals, 1 indoor gold and 1 indoor silver), but what jumped was football off the charts and into the money during a huge economic recession/depression - All other sports took cuts while football added resources more and faster than at any other time in their sporting history.
On the surface, it does seem like Volleyball should just be exploding across the USA sporting landscape but it has 'seemed' like this for 20 years. As long as Football dominates the conferences, Basketball dominates the NCAA and we don't have the leverage of Equity, things will continue as they always have.
My opinion is the largest and most explosive segment of volleyball in the country is club volleyball. Club Volleyball is rapidly growing the south-southeastern part of the USA. There has not been an equivalent growth factor in funding or popularity of collegiate volleyball; the base is huge and to collegiate athletic directors, wonderfully silent.
In terms of PSA's, this continuous growth of the sport among high school age players, has led to a very competitive recruiting and college volleyball environment. In a very real sense, there are a lot of very good volleyball players (and the talent pool is growing every day) but the opportunities in college volleyball have not grown. This puts much more pressure upon VolleyFamilies to be active and engaged in the recruiting process, along with college coaches being able to change their rosters at will because they can replenish quickly.
To tie a bow around my entire answer; this is a prime reason why I joined NCSA Athletic Recruiting. I sincerely believe that I am in a position to help so many families by working with NCSA, than by just being a college coach (and I sleep much better!).