The claimed top speed of S Presso is 140 Kmph. Comparing the two variants VXI Opt and VXI Plus, here you may find the difference on the basis of available features. For the detailed comparison, follow the below link - Compare.
FWD means that the power from the engine is delivered to the front wheels of your vehicle. With FWD, the front wheels are pulling the car and The rear wheels don't receive any power on their own. Moreover, Maruti S-Presso is a FWD car.
Maruti S-Presso is available with 145/80 R13, 145/80 R14 and 165/70 R14 tyres in different variants. As you want to use 165/70 R13, we would suggest you to exchange your words with the nearest authorised service center as compatibility my tyres with wheels vary as per the variants. Check out authorised dealership details.