You're actually talking about two different concepts as if they are the same:
Concept 1: All sins are equal.
Concept 2: All sins separate us from God
The first concept doesn't jibe with human reality, common sense, or governmental systems. For example, a parent won't apply the same discipline to a child who forgets to take out the garbage vs. the child who lies and sneaks out of the house. Modern governments don't apply the punishment to a murder and someone who has run a red light. Even scripture, I believe, proves that the first one is false. All you have to do is read the Levitical laws and the varying punishments for the breaking of these laws. If all sins were equal, then why would they have differing punishments?
Having said that, all sins are the SAME in that they all lead to "death" (i.e. spiritual separation from God). Also, while we can engage in a thought exercise about the person whose ONLY sin is say...speeding. That reality would not exist. For example, in order for someone to consistently break a (seemingly small and harmless) governmental law, there has to be an underlying attitude of pride. Why do they speed? Because they are "safer" than other drivers, or their time is somehow more valuable, or the other drivers don't know what they're doing, etc. In other words, they view themselves as being above the law, or being a law unto themselves, instead of putting themselves into a position of submission. And, I guarantee you if someone suffers from the deadly sin of pride, it won't just manifest itself on the road. S/he will be lording it over family, or they'll be the "friend" who is constantly adjusting/advising/correcting, or they'll be the person in the pew praying, "thank you God that I'm not like the screw-up next to me."
Do we take it seriously enough? Probably not. I don't know of any person who really takes all of their sin as seriously as they should all of the time. I'm not even sure that it's possible to apply that level of intensity to ourselves. We're predisposed to justify all aspects of our behavior. Additionally, we live in a goodly amount of denial about some of it. Often when the Holy Spirit "wakes us up" to some of our sin, the loved ones around us are sighing with relief and saying "finally!"
What should the Church do?
The formula given for unrepentant sin is basically a slow build-up to excommunication or disfellowship. But, to continue with the thought exercise, is it really appropriate for a church to get so far up into your business that they'll kick you out if you have too many parking tickets? Do you really want to choke a (frankly) already overburdened ecclesiastical structure with these sorts of picayune issues?
The issues that the bible addresses regarding disfellowshiping have to do with enormously destructive behaviors--sexual immorality, following after idols, insidious false doctrine. I think if a congregation gets a handle on all of this, then maybe they'll be ready to move onto parking tickets and a failure to lower the toilet seat like your wife submissively asks.
Until then, I Cor 13 applies...."grace covers a multitude of sins."