[OneManWo1fPac]

Yes, you can place/remove blocks past the border if you're close enough. Also, I believe the border is actually at +/- 5001, so you should be able to purchase the realm with the outside spawner. As Prodigy said, though, if you own the within-border realm next to it, you can block people from getting close enough to mess with it.

if i purchase the realm at x:5001 do i get to explore the realm?

[olimar511]

No, you can still only go to 5001. I don't think there's any way to get past the border without it pushing you back. I think what Eah meant was that you can use sticky pistons to move blocks around past the border. If you can only reach, say, four blocks past the border, you can place a sticky piston there and use it to pull back a block that's six blocks past the border. Unfortunately, spawners can't be moved with pistons.

[OneManWo1fPac]

I FOUND OUT HOW TO MAKE IT A TTTRIPLE!