Hiya Scougar
I have been reading through the thread for you, now heres the deal (all bullet poins appologise if this seems condesending/repetative)
1- BT owns upto NTE
2- IT costs bt £150 per truckroll, so they have already spend over £300 on you

3- BT will come and fix if there test systems indicate a problem.
4- BT test system for linetests can return these results: Unbalanced cable, Frames fault, Dis one leg in network, Dis in net work, Loop detected, LTOK eu equip unplugged, LTOK eu equip detected, Earth fault, Battery fault, failed to test

5- to get BT to come out fo a fault ONE OF THESE needs to show up, this almost guarantees them to come out and sort it, unfortunatly advocating sabotage is not my style
6- To get bt to come out to do what you need done I would recomend ordering a broadband boost job, when the FE arrives ell him what you want done and it should happen, not joking don't give him a long hard time just tell him what you want done and he should do it.
Now the crackling is a GOOD thing, BT have to fix the dial tone first, it dates back to laws on providing communications in a no power situation. That crackling means the engineer has to fix that for you. At the same time asking him to repair the damaged cable that is Openreachs network and he should do that for you.
One thing to note: from that connector boix at the top of the door frame, one side goes to your ****y old master socket (which btw has no be upgraded as standard on any visit, so next time and engineer comes over make him give you an oppenreach nte

. The otherside goes to the next junction point, this could be going to OH or UG feeds, please bear in mind that if from on side of this it is straight through onto black cable, that goes up the house and over to the pole with no boxes or connectors (aka straightthrough from DP on pole mto your telcom box) then there is like 99% chance the Engineer wont do it, pole is most lkely unclimable.
Basically I see no reason for a FE to not come over and replace the master with an NTE and replace the cabling back as many junction boxes on ground level as you like. If it seems like its going to be a ball ache in your case then "grease the wheels" imo.