By Vectoring of VDSL the bandwidth can be improved about 150mbps. The advantage of this is same copper can be used. Will the service providers go for this kind of short term solution?
Looks that you are looking for a tutorial on the Vectoring of VDSL, have a look at http://www.ospmag.com/issue/article/vectored-dsl-rescue
Now coming to your second point will service provider go for it, answer is the yes. Access network cabling is one of the biggest issue in terms of cost and time so if anything which avoids that a provider would be happy to try.
Is there any relationship between DSCP marking and QOS handling in RAN?
How allocation of bandwidth (5/10/15/20 mhz) affect to mobile operator in the view of coverage, infrastructure cost, number of simultaneous users and system performance