The system wouldn't require many people to read much. Some gadflies, lawyers, and think-tankers would do a deep pass in areas that concern them; a citizen bitten by a specific law would look at that law in detail and register support/disapproval.
Then, the areas of controversy or obscurity would start to stick out in automated/ranked analysis. Activists (of all stripes) would point out areas for a closer look with URLs.
It is a system for calling attention to things, in turn -- not necessarily forcing preemptive review of (or expertise on) everything.
It could also work if the only people who register support/opposition are elected legislators. In this variant, by default, if you've voted for a law, you're marked as supporting all its clauses. A legislator can then go in -- after the fact -- and remove their name from those clauses they don't specifically support. (When replaced, the new seatholder inherits the previous legislators' positions, until they choose to update them.)
If/when a clause has zero supporters -- no one in the current legislature is willing to go on record as sponsoring it -- then it enters a sunset period. If it doesn't get another on-the-record defender in 6 months to a year, it expires.
Thus, every law, when passed, has coverage for every clause -- but then legislator shame and/or turnover leaves the most embarrassingly narrow clauses with fewer and fewer supporters facing more and more negative attention.
Compare it with the "enforcement priority list" for crime concept about midway through this piece:
http://www.nytimes.com/2009/10/04/business/economy/04view.ht...
By focusing attention on one egregious clause at a time -- as the 'least sponsored' or 'most opposed' -- the normal unaccountability legislators enjoy, because citizens are distracted and their concerns are diffused over the entire legal code, can be remedied.