Have looked at your radiograph.

Apparently there is some bone loss on the distal of 47 (#31)
and 48 (#32) is mesio-angular impaction.

Doubt that #32 would erupt into a satisfactory position.
Also note there is a large calculus (tartar) deposit on the
distal of #30.

My recommendation is to have RCT #31,  extract #32,  and then
have a crown placed for #31. In that order.
A bone graft may be recommended to fill the defect distal to #31.
IMO that is optional.

You will likely need scaling and root planing to adress your
periodontal condition.

Also note that there appear to be residual roots in the
area of #14 (2-6) that should be removed. You could
have a bridge or implant placed to replace this tooth.

BTW that was a great post of your radiograph, hope this helps,

    Good scan.  Extraoral films aren't the best for evaluating caries (or
periodontal disease) so you should take what I say with a bit of salt.
An intraoral film should give better detail.
    This is a gray area, and while the second molar is possibly
salvageable, note that there is significant periodontal bone loss on the
distal root (below the caries.  This means that if the root canal is
done (and BTW I see no reason based on the x-ray why the root canal
treatment could not successfully be done), you would still be left with
a periodontally weakened tooth.  Furthermore, in order to crown this
tooth it may be necessary to remove soft tissue to get a good margin in
this area.  It is possible that a periodontist could graft the defects
from the periodontal bone loss and that resulting from the extraction.
But there practically may be a limit to just how much dentistry you're
willing to go through when in the end you will get a somewhat
compromised result.
    I would certainly NOT depend on the third molar erupting into normal
position for the second molar, although this might be accomplished by
orthodontic guidance.  I'm also not totally comfortable with
recommending using the third molar as an abutment (holding) tooth for a
fixed bridge.  An implant-retained crown (if possible) would be a better
option IMO.
    Lastly, you do not say how old you are, but you also show signs of
early periodontal disease in several areas of your mouth.  Furthermore,
the amount of tartar visible on x-ray indicates that you are a heavy
tartar former, have inadequate oral hygiene, or both.  You should
improve your oral hygiene esp. with daily flossing to prevent
progression of your gum problems.  Speak with your dentists about the
details of managing this condition.

Steve