Teleportation Woes
I generally prefer high level campaigns myself, so I can sympathize with your concerns. Teleport has a rather significant weight limit. At, IIRC, 50 pounds per level, it takes at least a 13th level wizard to transport your typical party of four.
Wizard- thin frame, no armor, no gear: 100 lbs.
Thief- thin frame, light armor, light gear: 150 lbs.
Cleric- medium frame, heavy armor, light gear: 200 lbs.
Fighter- heavy frame, heavy armor, heavy gear: 250 lbs.
If you add up the above weight it comes to 700 / 50 = 14th level. Still, you may have a light, trim fighting force of elves and halflings. Even so, the above party would be, say, 100 + 100 + 150 + 150 = 500 / 50 = 10th level wizard.
After making up a set of stock backpacks my players could choose for new characters, most weighed in at about 40 lbs. When you include heavy armor, weapons, and a shield, the gear alone comes to 100 lbs. Back when I was fit, and young, and I did a hundred push-ups and sit-ups to warm up for my workout. I weighed 160 pounds. So, that’s where I got my fighter weight from. Even so, there are professional wrestlers, NFL linemen and heavyweight boxers that weigh 250-300 pounds naked. So, your human, dwarf or half-orc who has a high strength and constitution may weigh, with gear, 350-400 pounds all by himself!
One thing I have done to minimize bookkeeping is to use the above shortcuts and to institute a “block rule” for teleport. Weight must be distributed in 50 pound blocks. Given the non-anal retentive bookkeeping that most groups have with regards to mundane equipment and its weight, these shortcuts make things easier when determining teleportation weight. We haven’t even considered the loot yet, either.
So, that’s the weight issue. Next, impediments.
Hallow / Unhallow has already been covered, and I’m sure that Forbiddance also blocks trans- and pan-dimensional travel. There is also a tradition that lead has significant anti-magical properties. A room paneled in lead sheets is proof from scrying and teleporting. This isn’t truly feasible for a large complex except for specific, key rooms and locations. Also, there is also a tradition of areas of easy / difficult teleport access depending on ley-line locations. Since those are known about, they are sought after as either hubs of travel or secure locations. That’s pretty campaign specific, however. Still, that kind of “nerf”, if you will, is readily accepted by players when it is known at the start of a campaign.
Tone.
Claustrophobia and paranoia are fostered not so much by not being able to retreat, but by not having a safe place to retreat to. When my players where doing the scry / buff / teleport tactic to select enemies, the foes retaliated by sending an elemental horde against the town. Six large fire elementals with two huge earth elementals lurking underground work wonders on destroying a 3,000 person town. Particularly when the earth elementals suck the few people who can harm the fire elementals underground. The players teleported back to their home base and found the town a whirling inferno. The only safe place was the temple where they teleported to, and that was packed with refugees. They waxed the elementals in short order, but not before the town was ruined. The place that they had used to rest, resupply and recuperate was gone.
If you are looking to run the PCs like rats in a maze, at this level, that is difficult to do unless you declare that either the terrain does not allow for a teleport or that the spell is not available to the magician. For myself, I make sure that there are consequences for bailing out when things get difficult. Be that the possibility of a trace, limited distance traveled or even the lack of opposition that the foe now has since the heroes fled.