1) You can't abolish legally binding precedent in America. Without it, you lose your incorporated rights from the Bill of Rights. You'd also instantaneously make most of the US Government unconstitutional. Go read Marbury v. Madison. Judicial review is an important part of our system. How the hell would you get a 'consensus' of the legal community without the current court system of trial court to intermediate court to court of last resort? So Texas and California should no longer have their own laws and be forced to come under a single Federal law? What about the Federalism (that means states rights, not stronger fed power) that's built in to the Constitution? What about letting cases percolate over time in the system so when the high court finally reviews them, they can make an educated policy decision? Many times the 'moron's' decision 150 years ago is modified ad nauseum. Some very important ones stay around;
2) Hire someone competent? HAHAHAHA. What makes you think that the "competent" person wouldn't be subject to the same difficulties in drafting law, or be subject to heavy-handed lobbyists? Law is like sausage, you never want to watch it being made, but it usually turns out ok.
3) I don't know about what laws you're looking at, but finding the current law in statutory or regulation form couldn't be easier. It's almost all on the internet. The amendments are listed because it lets the attorney determine what law was current AT THE TIME OF THE EVENT OR OCCURRENCE IN QUESTION. See, our Constitution has this pesky no ex post facto laws clause... meaning most cases are tried under the law at the time of the event causing the suit. Frankly, I'd say that the US legal system is one of, if not the most organized creatures on the planet. And it's all a few click away in search engines that make Google blush: LexisNexis and Westlaw. (not free though)
4) Laws aren't exclusive... when judge application of law turns out wonky... we almost always get the case overridden by the legislature. Remember, case-law fills in the gaps of the legislature's text. I.e. the judge can fill in the small details, the fact nuances, and unexpected applications... and if the legislature doesn't like the result, they can just amend the law. Checks and balances. Even if there's no law on point, you have to determine whether the novel conduct was legal AT THE TIME IT OCCURRED. Meaning that if there were no laws on point then, you have to determine whether it was legal by twisting and contorting (heh. torting) the then existing laws.
5) The trend in law is to not use jargon; briefs written by modern attorneys that didn't go to a snobby school are typically well organized and written mostly in layman's terms. Latin is kept to a minimum i.e. say 'claim preclusion' instead of res judicata. Both mean the same thing to an attorney, but it's also easier for the layman to pick up.
Is the system perfect? Hell no. But I'd stay in a common-law system over a civil law system any day. You want to give judges even more power? Fucking nuts. Adversarial is better than inquisitorial.
We'd have to have a complete revolution in order for your proposed changes to come about.