Cubchai definitely cheaper to maintain in the long run...

1. Scoot need to change the CVT parts.. Belt, Roller and Clutch  just its need different KM distance on those parts.
2. Engine oil will need to change with oil filter (compare to EX-5), and good quality of engine oil needed since Scoot with CVT will need to operate in higher RPM most of the time...
3. Those fat but small Tyre definitely more expensive than those cubchai rubber (unless you take the standard size 14 or 17 inc tyres like those PCX or Nouvo)
4. Bodyparts.. more plastic cover need to maintain.. if you tend to leave your scoot under the sun most of the time.. forget abt it.. will fade and crumbled..

Those scoot you mention does not guarantee long space for your leg, just same as cubchai... but if you really into those choices..

I would suggest Honda Spacy as 1st option then follow by the Ego .. dont go for Modenas.. how many you see on the road this bike?

And don't go for Suzuki as well.. their principal close shop in Malaysia only Lion Suzuki as distributor now... even in Thai and Indon Suzuki not  mainstream brand...

However, Suzuki tend to build their engine tahan lasak...

Ride that far daily? Salute you 
v-belt sets not that expensive (Yamaha). My Ego LC Fi, as stated in manual, need to change every 20k. My annual mileage only 6k. So it'll take years before I need to change it.

I still have my first scooter (Yamaha Nouvo first edition), pass it to my brother. Still kicking strong. Only the plastic cover faded.
1. Mileage base. Not that expensive.
2. Every 4k km.  Similar with kapchai. Similar engine oil spec. Nothing fancy.
3. True. Can be significantly expensive.
4. Similar to kapchai too. Most kapchai also covered with plastics.
I use Ego LC Fi. Good enough to go to pasar malam and work (10 mins ride only). The only thing that lacks is fuel tank too small 3.8L.
Which version do you have?