Is this merc good or not?

https://preview.redd.it/qhbym2j42qnh1.png?width=3222&format=png&auto=webp&s=1f9796f7d38a5587dceae8e051297eac6bf3d424

Here are my 3 questions.

1. Is this merc good or not? Or should I farm a new one?
2. Got 2 Rathpith Globes so can I try to vaal one of them to get a 4% one?
3. Got only 1 Kaom's heart, can I try to vaal it to get more life? Or the risk that will destrory the armour is too high?
4. What is the tree to get foulborn red dream with 50% life mod? I tried a whole week, still none. Here is my tree.

https://preview.redd.it/k9ihnwm33qnh1.png?width=1227&format=png&auto=webp&s=858c0908fbac3ac8f55fb47e2bb5154a1648c866