I think you need to have some interest in PvP to feel at home in IC. I recommend duelling to every beginning PvPer. You could also "learn on the job", if you find that more fun. Either way you will be killed at first. Ganking isn't the only way that happens. You may also be zerged or, as an outright tank, you may be drawn into endless fights that prevent you from farming. It is for that last reason that nightblade is my favorite class in IC, specifically a magicka perma-cloaking speed build. This is the build that most allows you to do what you want, to disengage from PvP, to isolate bosses for solo farming, to bring your Tel Var home.

That said, there are other options. I've seen players, possibly it was a warden, so outrageously tanky their health merely dropped to 97% regardless of how I attacked them. However, I don't know what the build was. Another option is a (sorc) heavy attack build, simply because the tri-focus passive with a Lightning Staff can do so much AOE splash damage, you may casually wipe some nightblades by continuing with your boss fight.

Werewolf got nerfed a while ago. I have a sorc WW friend who PvPed on that class for years. His favorite. He gave up and is now playing that character as a regular sorc. Essence Thief is thought of as a duelling set. In open world things are frequently too chaotic for you to pick up the buff. Still, a health build with Essence Thief sounds like it may be viable for a WW. Worth a try.

I'm basically an IC specialist. It is my favorite place. Having started life as a DK, my own feeling is that there are only two classes for solo play, nightblade and sorc. Classes that specialize in movement and escape. If you play any other classe, if you favor tankiness over movement, it's possible to do just fine while your faction dominates IC. Otherwise you will find yourself:

• Being an outright troll tank, doing no damage.
• Experienced, but locked into an endless fight in the crevice between some stairs and a wall.
• Dead.

While you can always queue for and port out to Cyrodiil, in order to save your Tel Var, I prefer not having to do so frequently. A streaking sorc is one option to run away and is easier to play than a cloaking nightblade. The latter, though, is your best bet for disengaging from fights altogether. It's not always the best. Some enemies specialize in hunting nightblades and can make your life hell. However, on average, Cloak is IMO best for solo play and Tel Var farming in IC.

I don't know whether this would be up your street, so I'll merely outline my personal magblade build:

• The Esoteric Greaves will make you almost impossible to gank. Viable on magblade and magsorc.
• I build for speed, e.g. Steed mundus, all Swift jewelry, Concealed Weapon, Race Against Time, and so on.
• The combination of Rally and Siphoning Attacks can give you (near) perma-cloak sustain while moving.
• I use a Soulcleaver front bar. It's a good compromise for IC, e.g. for healing from damage during boss fights.
• I use Wyrd Tree's Blessing on the back bar. Cleansing all effects when you start cloaking helps with this playstyle.
• Balorgh for the damage. I am a PvPer after all.