Hey Kurt,
All very good questions, valid concerns and it shows that you're thinking about and visualizing what is happening to your gear while trolling.
That's the best way I know of to become a better fisherman!
When fishing a slider spoon you really need to pay close attention to your rod, swing hard and get on that fish as fast as you can.
Are you going to hook every fish that grabs a slider? No, but you wouldn't have had a chance at him without the slider working for you in the first place.
As far as what happens when it hit the clip? It's going to release although not as quickly as your terminal gear which is why you need to really tend your stick!
One more thing to consider: When a predator grabs a baitfish, he does not experience the immediate resistance that trolled gear imparts on a striking fish.
It's entirely possible that a fish taking a slider will get the hook more deeply due to the lack of immediate tension and that may lead to a solidly hooked fish... or, one that spits it out when he tastes metal!