I agree, with Darth Woo.   You should open them all if you want to display.  Looking down the road do you really want to burden your children with getting rid of all your stuff, which may have no meaning to them?   For myself as I think into the future, once I retire more than 10 years from now.  I plan on getting rid of most of the stuff that holds little or no value, as I don't want to leave it for my kids to deal with after I am gone.

I'm in a similar situation. I'm an opener as a rule, but I've also never gotten around to opening most of my collection. My thinking was to leave them in the packaging until I'm ready & sure I want to set them up in a display. That way if I lose interest in some things, get better updated versions, or just need to cut back on volume, I'll hopefully be able to sell off the excess for a better price. I'm really not counting on having this stuff to leave for my kids when I die - I doubt there will be much value there in the end, and I'll likely end up selling as much as I can once I hit a certain age.

So yeah, to kind of echo what JJ said, see if there's anything you can just sell off as well. For me it was my entire Clone Wars collection (all still carded) and a whole lot of boxed ships. I just wouldn't have had the room to do anything with that stuff. There's a lot more I can still get rid of that I'll get around to one day soon I hope. If there's stuff you know you'll never part with and plan to include as a part of any displays, go ahead and open those. But if there's some things you aren't sure about, keep it sealed for now until you either open it or sell it.

I open most of my stuff. If you have older stuff still in package I would only keep carded what has significant value. This way you can open most things and have a few special items on card.

Interesting thing I just thought about, as we talk about trimming down our collections as we get older, who is going to buy it?  As the majority of the collectors will be in our age group and most likely be sellers not buyers for the most part.

This is exactly why I have no interest in keeping these things as an "investment". They are so mass produced, and the buyer-to-seller ratio is only going to get worse over time. If you have anything that you're no longer interested in for the fun of it, get rid of it now - the market is probably at it's best for modern figures.