I have a simple question
*What level are we talking about!!*
Whether it is a problem or not, and what solutions there are, seems to depend greatly on what level campaign we are talking about.
Some non-meta-game thoughts on the matter:
"Studied carefully" means that you have *studied* it. Sure you can do it via scrying, but not just once... It is up to the DM to determine how much 'study' is enough. You can easily say it has to be 1+ hours (scry is 1rd/lvl) so that is a LOT of scrys. That would make it a cool tactic, but one that takes several weeks to set up.
I would say the sameish for 'seen casually'; lets say 15-30 minutes.
'Viewed once' should be *more than 1 second!*
Think about it, the idea is to cast scry, and then teleport the next round, so you get to look for what... 1 second? It would be logical to say you had to view it for at least 30 seconds...
Teleport weight: remember, it is just 50 lbs/lvl. An average 1/2 Orc is almost 200, plus armour, plus weapons, plus rations, plus gear, plus....
You could even make a case for the wizards belongings adding to the weight. Sure, you could probably take a bunch of gnomes....
With these interpretations, it relgates B-S-T into taking days/weeks to set up, or relying on 'viewed once'. This has a 25% chance of error, and as the DM, I would make it a pretty costly error. (okay, maybe a *leeetle* bit of metagaming..

)
Readied/held actions: I don't think I would allow someone to have a readied action through a teleport, but I will have to check to see if that is an interpretation, or a house rule....
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