Looking good so far! A couple tips I can offer:
Try the runeword "Stealth" in a two socket armour (breast plate best style on barb IMO, you can shop them from Fara in Act 2). Can get the runes super easy from Countess and it offers some great early game bonuses.
Secondly, once you get to slightly higher levels you might consider Frenzy. No defense bonus on attack but damage will be much better and it's still uninterruptable. Going without a shield may feel scary at first but as long as you've got hard hitting weapons and some life leech you'll tank like a boss!
Regarding dealing with physical immunes later in the game, one point in Berserk can be useful, just be sure to accompany it with Howl spam as 0 defense + no shield = potential ouch. Ideally you'll want an Act 2 Might merc (offensive from NM difficulty) with Reaper's Toll. Before that, if you're using ladder rune words, Lawbringer on an Act 5 mercenary also works great, especially on boss runs like Meph, which is the primary stop for item upgrades for many WTs.
Good luck, will be following, barb for life