my tp is on july hoping to pass ^^

hi guys. im a singaporean living in malaysia...looking for a 4 stroke dirtbike

lets say its around 15km ride from custom to my house..and im working around changi area..and im going to pillion my dad to work too

1)is it avisable to get a dirtbike?? i really like the looks

2)how about the monthly maintenance and fuel consumption ? is it cheap?

3)how about the parts ?is it still available ? New sits , mirror , breaks , tyre etc etc...

4)how is the controlling in jam's with and without a pillion ? (custom)

5)should i do a overhault and a full service when i buy this bike ?

6)do malaysia workshop reconize this bike ? (servicing ,changing of parts etc etc)

7)from what i notice most dirtbikes are made in the 1990' there any in the year 2000's with a good pricing ?

8)is it true i cant drag the bike ? i have to play with the gears in high way ? 0_o

sorry for asking too much

sorry for asking too much