It's fine to hand express, and a lot of women find it easier to do so, once they have the knack, so you really don't need a pump. Try hand expressing before you shell out :)
Partners really, really don't need to feed the baby to have a relationship with the baby - there are loads of other things to do and share with the baby. Fathers who don't give a bottle of EBM are no less involved than fathers who do - my dh never did it and he would take exception to the idea that he was somehow left out or less close to the children as a result.
There is nothing wrong with a father doing so, of course, and fine if you both want it! But I have seen expressing (so the dad can feed ) become a bit of a chore. Not everyone finds it easy to express, by hand or pump, and missing a direct feed (because dad is doing the feeding with the ebm) can mean your breasts are uncomfortably full. Having said that, for some couples it's worth it. And it's a useful thing at the times you have to be somewhere without your baby, whether it's your dh or someone else giving the bottle.
You could try it, once you feel confident and relaxed about the whole baby and feeding thing, and see if it works for you - but don't be worried or think you have let anyone down if you feel it's a hassle or you don't have time.
Keep an open mind :)