I've not gotten too far into it. Walter went straight to Vault 111 and the main quest has you find a hollowtape recording of Shaun's kidnapping. You're then tasked with reporting it.
I've only spoken to Codsworth regarding the main quest so far. The conversation largely plays out the same, though your character's responses are all different. Codsworth has you confused for his previous owner, which your character puts down to a malfunction from 200 years with no servicing and so on.
Tomahawk is going to avoid Sanctuary and Vault 111 completely. Will be interesting to see if they've covered all possibilities when she get's to Diamond City. I highly doubt it, but for now it's the best option and it's working a treat.
Aaand HOLY CRAP, it gets a pass! I got to Diamond City with Tomahawk having completely missed Vault 111 and any mention of Shaun. When asked by a number of people what brought me to Diamond city, I could either keep it to myself, say I was just passing through or say that I was looking to do some trading. Well played, mod.
Speaking of Diamond City, it's a good way to get a new look if you're considering say... terrorising the Commonwealth. She's proving to be a real fun character to play as. I didn't realise stealth would be so amusing. I heard two raiders talking about a settler who did a Micheal Winslow routine
to trick them into thinking he had grenades and a machine gun, before pretending to ride away on a motorcycle.
Shortly after, she thwarted a would be ambush by entering through a locked door and quietly dispatched the whole crew of raiders with just a combat knife. Really quite satisfying!