Ok, so here's the thing... you are not supposed to be able to do optimal damage with Heartseeker and Cascade. This is not a bug, this is a feature.
Let me explain: All heavily multi-hitting high WDM skills are locked behind some kind of game mechanic to balance them. Here are some examples:
- Cherubim is locked behind having to use a one-handed weapon (hence, lower base dmg)
- Hammer of Zerae is locked behind using scepters (hence, lower base dmg)
- Fussilade and Broadside are locked behind pretty big cooldowns.
- Homing Nova Shot had 100% fire conversion to avoid leech abuse and was locked behind a specific SU.
There are many more examples, but you get the idea. Spamming Heartseeker and Cascade without any limiting mechanic would break the character. You can easily see how this would happen, since one successfull proc of the bear buff, if taken advantage of correctly, can decimate almost any bosses hp in just a few seconds. Reworking the mechanic for Heartseeker and Cascade would mean reworking the entire Hunter tree (again). This would theoretically make sense if the build was useless without being able to spam those skills... which it certainly isn't, and you can check the other bow druid thread to gauge how much success other people have had using this build. I mean, there's literally a video of a guy farming fauzt potionless in 5 minutes with the build. I've leveled one to 125 myself, and it was one of the easiest experiences doing that so far. Doesn't sound weak to me.