the heatshrink are better qualities actually, you get better results during sleeving.. the sleeve are also more compact so even when you extend your sleeve a little bit you wont see the cable inside..

The heat shrinks are also better because they shrink well compared to others

Any lighter will do the job, not necessary this brand.
But be careful while heating the heatshrinnk as Mr clawhammer said.

And need time to take out all the old sleeve check every wire, replace new wire when necessary.

Perhaps this link can help.
http://en.mdpc-x.com/

Totally agree.

shrink ratio also bigger