Right, taking your objections once at a time:
The bad luck of having a funeral on Friday 13th will hit your family if you're there or not as I understand it is having the funeral that is bad luck, not attending one. So that's no reason not to go.
Re wearing black on Friday 13th (first time I've heard this one, BTW - that's really not a common superstition) - dark grey or dark navy would also be acceptable colours for a funeral outfit, and you have 2 weeks to take back your DC's and your outfits and get ones in dark grey/blue ones.
re the funeral procession passing you meaning you'll die within the year - won't you be in the procession cars, not having it pass you? so it'll be all the people who you drive past who'll be risking their lives, not you. (obviously if you genuinely think everyone you drive past will die, I can see you might think it's not a very public spirited thing to do). If you can't even be in the cars, would your DH mind if you travelled to the church on your own and took a different route?
And finally, re your DH not considering your feeling when arranging the funeral with his family - his father has just died, your objections to the date are very unusual and obscure superstitions, if you believe them, then fine, but the majority of people will never have heard of them, let alone believe them.