strata titles (also for landed) is governed by the terms and conditions in the DMC.

now why the hassle? it is so that every one in the community plays their part in the maintenance of the neighborhood. usually this is necessary in creating/maintenance of a lifestyle. you can't do that with individual titles as no laws bounds one owner in participating in maintaining the common areas (unless they enter into another agreement altogether). Strata titles also mean the areas can be marked as private for residence (like gardens, roads etc). In an individual titled area, all other common areas are accessible by the public by law

it is not true for a strata title property no extension is possible. usually the DMC will govern this and you will need to obtain permission from the property managing body.

as for the effect it has on the property, really, strata/individual title is pretty much the same.

you need to get all necessary permissions before starting of course in accordance to your DMC. it is true some DMC specify restrictions to extensions - read it if you are in doubt. if you have all the permissions and you are following all the rules as specified, you are pretty safe