ps3 i s much better

If you want comfort and quite ride, 3ST is designed exactly as your requirement.

And don't forget to check with the shop around how many thousands of kilometer usage then you'll need to do tyre rotation, balancing and alignment.

I've tested 3ST tyre before, high speed wet and dry cornering, the tyre still stick to the road, didn't feel losing confidence with it's grip. Of course I don't recommend you to try the tyre limits on the road or even on track, it is designed for road usage, not racing or even drifting.
Sorry if this offend you, no meaning to attack or anything. I'm really intrigued how you know PS3 will last a bit longer than RE003? Especially when RE003 just came out 2 months ago.

mazda 5 use primarcy lc for quite and conform.  ps3 is for sporty ride.

If the shop give you free alignment due to buying 4 new tires then just go ahead. If not free then no need, you can just try it first to see how your car feels after tire change. If you feel the steering is not straight anymore then do alignment, if not then why need to pay for it?

As for camber screws, again the same, is the camber measurements really out?? If not then why need to have? So pay attention to your alignment measurements and see if really need such camber screws, don't just blindly follow what the mechanic tell you because more often than not they will try to con you to spend as much as possible.