How to manage bond points?

There's no benefit in getting everyone to bond level 5 except some useless text about them that you can read online. I'd advise you to get as many 5* servants in your main party because these give you 3 SQ for every bond level starting at 6 which is pretty good. Regarding bond 10 CEs, obviously heracles' is the best, but David's is pretty good as well, giving you a 10% chance to instantly kill when attacking as well as +30% NP damage. For me darius bond is good because I like buster effectiveness and I grailed him 90, but that's irrelevant to you (unless you wanna add me in NA: 960,131,323). Other than that forget bond levels exist, keep playing and farming as usual and after about 150 days you'll get to level 10 bond. That's a long time so don't think about bond levels and they'll magically come to you on their own as time passes, there are no shortcuts unfortunately. Just keep the six you want bond points on the most in your farming party, switching between different servants is bad for bond points because it slows down bond gain.

Getting everyone you can to bond 5 is a good idea on everyone that has an interlude based on bond, the interludes give saint quartz. Getting from bond 1 to 5 is far easier than getting someone from 5 to 6 let alone 5 to 10. As for bond craft essences they are generally not super incredible compared to a 4* or 5* craft essence, a large number of them give your party a 15% buster boost or something similar. There are a few exceptions like Heracles which are really really good, his for example gives you guts automatically 3 times when he dies, this along with his guts and dodge skill make him near unkillable.