Do you then drop the treat and just reward with a click?
No
A click is ALWAYS followed by a reward. The click is a marker that the dog is doing something you approve of, which is what earns the reward. Unless a click is always followed by the reward the dog will not work to acheive clicks...
Once a behaviour is learned you would fade the clicker use, and just use praise as reinforcement, alongside occassional rewards to keep the behaviour solid.
You can use a clicker to reduce undesirable behaviour, by getting the click in when they are not doing the undesirable behaviour.... so the millisecond he looks at the cat, but before he launches into a chase, click and treat. Then he will begin to associate looking at the cat with a treat, and chase behaviour will diminish. It doesn't matter what the dog is doing when you treat, so even if you click and he goes on to chase, he will still need the treat - it takes time, but eventually he will hear the click and look to you for the treat rather than chasing!!!
Likewise with jumping up - click and treat him keeping all 4 paws on the floor.
The very basic rules to remember with the clicker.
Click the behaviour you like - either by capturing natural behaviours, or luring if the dog is not offering a behaviour.
Click is always followed by reward - even if you have accidentally clicked.
You are looking to be click/treating very frequently at first - if you aren't getting about 15 clicks in within a minute (ideally more) you need to take it back a stage and give the dog a little more help.
Don't put verbal commands in until the behaviour is being offered reliably.
Clicker is NOT a remote control - don't use it to get attention!
The click basically says "I really like what you are doing right this second and I'm going to give you a really yummy treat (or a great game) just so you know what a really clever dog you are" - but it says all that in the split second they are doing the right thing, whereas even saying "Good Boy" can take too long if the dog is a really busy one!!