To me it seems like there's a lot of changes but they're all just for the sake of making changes without providing a real benefit to each line.
To start with, red line is in a good place. Don't make significant changes to it, instead use it as a baseline.
In my opinion, the aim should be to give each trait line a reason to be used, with 2 trait lines being desirable in instances/raids and one trait line being ideal for landscape. Making blue in to a melee hybrid doesn't make sense to me (people play hunter because they want to do ranged damage) especially as red would be able to dip in to blue for the inductions while moving, removing a key selling point of blue.
I believe blue should become a mobile burst/stealth ranged DPS line, while red should be able to provide more sustained high numbers as it does now. I would achieve this by moving the Hidden Stalker (+50% crit from stealth) set bonus over to blue line and separately modify camouflage so that it consumes 1 focus every 3 seconds but allows movement (this would allow other trait lines to move slightly in stealth, but blue would be able to move indefinitely). The addition of mobile stealth would make people want to play blue line more than they do at the moment. I know this encroaches on burglar playstyle slightly but I think one being ranged stealth and one being melee stealth is enough of a distinction to separate the playstyles, especially when neither red burg or blue hunter is the most used in raids anyway.
For me the issue with yellow line is that it tries to do lots of things badly rather than one thing well and these proposed changes don't really do much to help that. IMO you need to decide what role to fill and modify the trap bonuses etc to fit that role, rather than provide a bit of everything.
If you want yellow to be a CC build, give all traps stuns/roots, reduce distracting shot cd more etc, make decoy fear all enemies withing a certain range (essentially providing a protective bubble around the group for a short time)
If you want yellow to be a buff/debuff build, make all the trap bonuses do that - for example piercing could increase incoming damage, the one trap could reduce outgoing etc, the decoy could debuff all enemies in its range.
If you want yellow to be a healing build (not recommended), give the traps bonuses similar to piercing.
I like the fellowship purge poison cd reduction to 12s, please make it an optional trait rather than a set bonus though - in some instances purging everyon's poison isn't the right thing to do and more control is better. Also make it able to be used while moving.
A final request which doesn't specifically relate to the trait trees, but the hunter does have a lot of interesting skills which could be reworked slightly: Tracking enemies doesn't need 3 separate skills - just clutters the quicklsot bars when a single skill to track all types would work just as well.
Make campfire provide more benefit, maybe give it a very small AoE HoT - not enough to main heal anything by far, but just enough to provide a tiny benefit to the group