So I am working on finally maxing out my companion's affection to 10k. Other than taking less tine to gather and craft, and + to crit chance, what benefit will it give my character. I heard somewhere that it gives permanent stat bonuses + to accuracy, crit chance, etc...

1.do I just have to max out my 5 companions on this toon to get the permanent stat bonuses, or do I have to max out all companions with different toons?

2. do I just need to get them to max affection 10k/10k, or do I have to complete all conversations?

3. where do I find these bonuses in the codex?

Open up your legacy panel and look near the top for the Character tab. That will show you a screen split into 4 sections, one for each class, and each of those will show 5 companion slots. Hover over that and it will tell you the bonuses unlocked when you finish the conversations with those characters- it's for finishing the conversations with them, not for reaching 10k affection.

Each one maxed will give a +10 bonus to presence on all characters, plus the individual bonuses when using that type of companion in the future.

1.do I just have to max out my 5 companions on this toon to get the permanent stat bonuses, or do I have to max out all companions with different toons?

2. do I just need to get them to max affection 10k/10k, or do I have to complete all conversations?

3. where do I find these bonuses in the codex?

1. You get a +10 presence bonus for each companion you finish their conversation quests. The other stats (+1% accuracy, crit, etc) only apply once per companion 'type' (ie ranged tank, melee dps etc). These bonuses are applied to all characters in your legacy. For example, I have completed all of the companion quests across all of the eight base classes, so I have a +400 bonus to my presence score on all of my characters.

2. You get the crew skill crit bonus at 10k, but the stat bonuses do not apply until you finish all conversations - and you don't need to have 10k affection for that. Just get far enough in your class quest storyline.