Hi madirose!
From what I've read separation anxiety is definitely normal between 6-9 months, and I feel like my touchy LO has had it from day one, lol! My husband cannot calm DD at night at all either (honestly, it took 2-3 months before they even were able to get a good father daughter bond). So, we've just kinda split all of our duties, I do most of the feedings and comforting and bedtimes, and DH does the playtime when he is home. We started having DH give her her bath at night, but she's teething and started getting upset during her bath, so I started doing the bath again...we worked in a bit of daddy time between bath and bottle for DH to sit and read with her, or just chat since he is now missing out on bath time.
I think you should definitely prepare yourself for the possibility that she may not outgrow this. At least that's what we are trying to do
DH now understands DD a lot better, so we've taken on the team approach with relatives. He will lay down the law at any of his family functions, and I do the same with my family. Luckily I was a very touchy baby, so I have support from my own mom. However, our LO is the first really touchy baby in my husband's family, so it's been a little more difficult for him. His mom is taking DD's stranger anxiety very personally, almost like she thinks its intentional, that we created it, or that our baby intentionally does it to make grandma upset (weird, I know). DD is also very observant, and loves to look at everything, but as soon as people get too close she gets upset, so we have a bunch of things that we've started doing to make things easier for our LO. We started taking her to a quiet room as soon as we get to a gathering with a lot of people, we take her out of her car seat in the quiet room, and then slowly start bringing her out to the action. Other people can hold her, once she gets used to the noise, movement, etc. BUT, we always have them hold her with her back against their chest, not over the shoulder or cradled, that way she can see us and all the things that are going on that she really wants to see. We also gave DD a blankie. We just used one of her cotton receiving blankets (we have two of the same pattern, so we always have a backup in case one needs to be washed, lol). I think introducing a lovey will help your little one. We pull her out of the action if she starts to get fussy, and we go do something that she likes to do at home (we've started bringing her jolly jumper around to every house we visit, lol). Once DD gets older we fully intend to bring some toys and books to strange houses and set up a safe place for her to escape to where she won't be bothered if she gets overwhelmed (not sure how this will go over with the in laws, hopefully they will just learn to accept her personality and not try to turn her into something she is not). Hopefully you can figure out some things that will help your LO, remember that you are her best advocate, and things may get better once you can start educating people on her signals, and what she likes (I find it amazing that all these women who have had babies will completely ignore my LO's actions and signals and just do what they want to do with her, so I've just started telling them what everything means! I am also not opposed to telling family members that my baby is not a doll, toy or dog, and that she is actually a person, lol)
Keep up the good work!
P.S. I think people forget that at this point everyone but mom, dad and siblings are strangers...which means that even grandparents are strangers when babies are young. It just takes time, and lots and lots of time for some babies to get used to even grandma and grandpa. Personally, I'd rather have a child that is weary of strangers, even if that means grandma gets a little offended at first