On stuff for first timers -I know not many will agree, but I happily did without the baby bath. I used to have a shallow grown-up bath with DD sitting back against my tummy. Given how tall she got so quickly, we probably would have only used the baby bath for a couple of weeks anyway!
And bags, yes, any old bag will do. Although baby changing bags have all the pockets, these become redundant as soon as you start to deviate from what that brand of bag considers essential ("what do you mean you don't need to take a bottle? well nothing else will fit in that pouch, you know!!!"). Much better if you already have a big bag that either goes in the wash or doesn't mean all that much to you.
As for pads, get in a few, but then see if you actually use them before stocking up - I was given boxes of the things, but I never once needed them. And yes, I know I'm very lucky in that regard, but I'm sure I'm not the only one.
Breast pumps - that's a tricky one. A big problem is finding out (after you establish whether or not you can express, and I'm sure you will) whether you get on better with manual or electric. I bought an electric at first, just assuming that, by virtue of being more expensive, it would be better. At first it got loads out, but then, I don't know if my boobs just toughened up from what DD was putting them through, but they stopped giving anything to the soft pumping motion of the electric. However, as soon as I tried a manual, out it all gushed. It was a bit unsettling at first, seeing my nipple stretch about an inch down the pipe, but like I say, I think my boobs needed the more strenous pumping action of the manual to compete with DD's efforts.
BTW, this might sound utterly gruesome, it really isn't. It didn't hurt at all, it was just a very different sensation using the manual pump.
So if there's a way you could try both, perhaps via the midwife or in the maternity ward, give them a go. Otherwise I would err on the side of manual. Unless others have a completely different experience of electric vs. manual. I've not even looked over on the breastfeeding boards.