Advice on old diseased apricot tree (PPV and more)

[imm3344]

Hi everyone, I am in need of some advice.

Our apricot tree is around 22 years old and about 13 meters high. For about 8 years it has been showing signs of distress. The fruit has dry spots (like scabs) on the sun exposed side and the seeds have large pale circles (no circles on the fruit itself). However, this does not seem to have any noticeable effect on the taste, size or number of fruit. Lately new shoots and flowers started drying up. Some of the branches seemed dried up and dead well into spring only to produce leaves, flowers and fruit later. This was more pronounced in the last few years when half of the tree produced leaves a lot later, and lost them earlier than the other half. Leaves look normal at first glance, but closer inspection reveals that some leaves have holes in them and uneven green color with light yellow patches. After a brief internet search, it seams our tree is suffering from at least one disease (the Plum Pox Virus). My internet research is not yielding encouraging treatment options. We recently had two nights of frost while the tree was in bloom (maybe this could explain dried up flowers, drying has never been as bad as this year). The tree is in ASH Heat Zone 5 and USDA Hardiness zone 7b.

I have several questions:

1) Is there a chance to save the tree or should it be cut down?
2) If our tree should be cut down, could a new apricot tree be grafted on the existing root system after the old tree is cut down? I worry that the root could be infected with the virus and grafting would only spreed the infections to new trees.
3) If we remove the old apricot tree with the roots, could a new apricot tree be planted on the same spot? Is the virus going to be present in the soil? Should the soil be treated in some way?
4) Is there a way to tell if a new apricot sprout is infected with the Plum Pox Virus? I have managed to grow a few apricots from the seeds of our tree that did not seam to have any rings on the seeds, but I am not sure if they are virus free.

I don't know much about trees so any suggestions, recommendations and comments will be greatly appreciated.