Regeneration Master allows for a very fast regen rate in the later game. Keep in mind, killing the mage minions is a 100% chance to drop a regen orb, so try to kill as many of the mage minions as possible to start grabbing loads of regen orbs.

Amplified Healing will buff all healing you receive from every source including regeneration master, savor the flavor, any heals from an ally and healing from your base or healing fountain. The most beneficial use of this talent i find is the increase to healing for regeneration master, by the time you are around level 10, you should be regeneration around 30-35 hp per second. That's pretty impressive considering you're only halfway into your talents

Savor the Flavor is less useful than the previous two talents, however it can add a very nice stack of hp per second, on top of the amplified healing and regeneration master. The main issue with taking this talent is making sure you don't rush the use of your Devour while at full health, in hopes of gaining the +2 regen and not getting the 20% healing effect.

Putrid Bile is less usefull at level 10 as it doesn't give any direct healing, however later in the game, you will be able to amplify this ability to also heal you. The main use of this ability until that time is i find, either rushing into a battle and laying down a poison damage carpet, or running away from a fight gone bad, and slowing your opponents to prevent chase. Until level 20, this ability is not the most useful when it comes to tanking, however it has saved the lives of my Stitches plenty of times and is therefore still a great ability to have.

Relentless is not useful in a tanking damage sort of way, however relentless becomes very useful versus enemies like Anub'arak, Muradin, Malfurion or Diablo, in that it reduces the duration of any disables by half. This is especially useful if you find yourself rushing into battle against a crowd control hero. If the enemy team contains no heroes with any significant disables, Mega Smash may be the way to go.

Imposing Presence is a very useful skill if you engage an enemy and quickly overcome them, as they try to flee they will have their move speed reduced and that, coupled with your hook, means you have a very significant chance of being able to make sure they don't get away. Alternatively, if you get bursted down, or bested in a fight and need to make an expeditious retreat, this talent will help slow any pursuers that attempt to continue to attack you

Regenerative Bile is where your heroic ability, Putrid Bile, helps you tank damage. If you find yourself being damaged by an enemy hero or 2 and your regeneration doesn't seem to be keeping up, you can drop the Putrid Bile and run in circles, both damaging your enemies and healing yourself for half of the damage dealt. Paired with the Amplified Healing talent from earlier, you will heal an additional 30% life. This also improves your escape plan as, if you get quickly dropped, you can use the bile, run away from the danger, and as you run any enemies caught in your bile will supply you with more life, in case you get caught in a fight on the way to the healing fountain or base