1. Hold Position
2. Continue
3. Feuding With A Young Up & Comer
When it comes to RVD's position in WWE, there's not really much you can do with someone who wrestles for 90 days before taking time off. You couldn't give him any sort of lengthy run as champion. The best you can do is to use him as a possible title contender without putting the title on him unless you want WWE to go back to playing hot potato with championships.
As far as his character goes, might as well stick with it in my opinion. RVD doesn't exactly have the best promo abilities, nor is he particularly good at acting to any appreciable degree. Frankly, I'm not at all convinced he's capable of doing something deeper or darker. The RVD we see on television is, for all intents and purposes, who he seems to be in real life: a mellow, laid back 43 year old stoner.
As to who I'd put him against, I like the notion of him going against Cesaro due to his connection with Paul Heyman. We've yet to really see any interaction involving RVD & Heyman since RVD's return to WWE. Cesaro has momentum right now, RVD is a well known star who'll probably go back on hiatus after SummerSlam, so having Cesaro go over in a feud with him is a good use of RVD's limited time. As I said, he'll probably leave after SummerSlam and probably won't be back until it's time for the Royal Rumble. As a result, feuding with and elevating someone like Cesaro is the best and most realistic use of RVD, in my eyes anyhow.