Also, invest in a backup strategy and charge accordingly. Once you accept the money, 'sorry, lost it' is no longer acceptable. You need immediate image backups, plus offsite backups asap, plus backup hardware.
Anyway, 400 quid is peanuts. I've heard of people paying 10-20 times that amount while not even expecting top class shizzle.
Along with the backup strategy, get proper insurance. It'll cover you in case you have that "oops" moment, or disaster happens, or you know over old Uncle Phil and break his hip when he's trying to get the shots after you wrangle the family for a few minutes for the formal shots.
Also, about that price, if you've got 10 weddings already and haven't been charging and have some great stuff for each wedding, start charging a lot more. For the £400 you'll only get real cheapskates or people who really can't afford more. For the latter, maybe set aside X number of weddings you'll do a year for them if you want to sorta spread your talents and skill. For the former...it's going to be worse than usual since they'll nit-pick and expect you to turn out amazing shots at their cheap-ass wedding & reception.
Locally there are quite a few wedding shooters and I know they're charging at least £2000 (about $2600 ?). I don't think I could justify that to anyone until I have a proper gallery up online and a few printed examples.
I've seen a few photographers that shoot the day, do no post-production and just put everything up online, even the duff shots and charge per download. Is it just me that is precious about which shots make the cut? does anyone give the client all the shots from the day? a few have asked for them and I've refused as I don't want anything going out that's out of my control.
You make a point about having some prints and sample albums, as well as a better online gallery, but you don't have to start charging super low otherwise you'll get stuck there more often than not.
As for the shoot & burn (or charge per download), you have to make the decision if you want to do that or not. IMHO you should care about which shots are shown to the client(s). In terms of giving up all of the shots from the day, it's somewhat of a personal thing. Most wedding photogs I know of (mostly from this forum) won't show everything, and won't give everything they do show. You do need to ensure that you provide a good number of web size images for posting to FB, G+, etc. Otherwise, in terms of printable sizes, it's a really great question. Do you have them order through you (either directly and you go to a lab, or using SmugMug or similar high quality service)? Do you give them a sub-set of your delivery at full res for printing? Do you give them all that you deliver at full res? Do you charge more or less for more full res since you can't make anything off of the printing for them?