Conditionals

[jack]

Are these correct? If not, why?

1. If it could be like that, that would be very cool. (Is this correct with 'could' and 'would'?)
2. If it was like that, that would be very cool.

3. If it could be like that, that could be very cool. (Is this correct with 'could' and 'would'?)
4. If it couldbe like that, that would be very cool. (Is this correct with 'could' and 'would'?)
What do #3 and #4 mean?

[jack]

Are these correct? What do they mean?
1. We would have been done shopping by now if that wallet wasn't so expensive
2. We would have been done shopping by now if that wallet hadn't been so expensive.

[jack]

If these are not correct, why? What do they mean?

1. If this occurs, your brakes will funcion nomrally as if they had no ABS. (Why is it 'had' and not 'have'? How do you know which one to use?)
2. If this occurs, your brakes will funcion nomrally as if they have no ABS. (How come they don't use 'have'? How come the tenses don't match?)

3. If the ABS warning light stays on while you're driving, the ABS control unit has detected a system malfuction.
4. If the ABS warning light stays on while you're driving, the ABS control unit detects a system malfuction.

5. If I had gone there, I would have bought you that. (Past Perfect + Past Perfect. How come #3 isn't like this? Like it isn't Present Perfect + Present Perfect, it is Present simple + Present Perfect? And that is right?)

Are these conditionals? How come the tenses don't match? The verb 'was' after the word 'main' doesn't match with the other verbs?)
6. If something beside the cruise main was used to cancel cursing speed and the system is still activated, the most recent set speed will automatically resume when the control lever is moved up to the RES/ACC position. (This is the one used in the book. )
7. If something beside the cruise main is used to cancel cursing speed and the system is still activated, the most recent set speed will automatically resume when the control lever is moved up to the RES/ACC position. (How come the book didn't use 'is' instead of using 'was'?)
8. If something beside the cruise main were used to cancel cursing speed and the system is still activated, the most recent set speed will automatically resume when the control lever is moved up to the RES/ACC position. (Is this correct with 'were'? This is subjunctive?)

Same with this one. How come the tenses don't match?
9. I can think of only one reason to disengage the transmission at a stop. That would be if your idle speed is set too low/high. (This is the oringal sentence. )
10. I can think of only one reason to disengage the transmission at a stop. That would be if your idle speed was set too low/high. (How come they didn't use 'was' instead of 'is'?)

For the two sentences below, they're not conditionals right? That's why the tenses don't match right?
Original sentence:
11. If your car was only equipped with 2 snow tires on the front (front wheel drive), there is great possibility that when you begin to slow down your rear may drift to the side, and vice-versa if the snow tires were placed on the rear
How come #11 isn't like this:
12. If your car is only equipped with 2 snow tires on the front (front wheel drive), there is great possibility that when you begin to slow down your rear may drift to the side, and vice-versa if the snow tires is placed on the rear

Both of these are correct right?
13. If there was a subsequent collision, a damaged sensor would not inflat the air bags.
14. If there were a subsequent collision, a damaged sensor would not inflat the air bags.

Thanks.