I agree. However, that would send LOA prices through the roof.
I can't think of any deck right now which could abuse LOA. A gifts variant, perhaps?
Old school Landstill gets amazing now? No. I think unrestricting Library of Alexandria is a good idea for the metagame.
Unrestricting Library being good for the metagame is like saying that getting shot in the face is good for lifespan.
If it's unrestricted with everything mentioned in this thread, it wouldn't even be played as a 4-of, because there is no reason to. You are playing in a format with 4 Demonic Tutors. There would be 3 kinds of decks: Retarded Combo, Stax, and Hope To Get Paired Against Stax.dec. HTGPAS would play Libraries, but it has 2 answers to Retarded Combo: Force of Will and Unluckyman's Paradise + Force Spike, neither of which are particularly good at stopping RC.
If it's the only unrestriction, more decks will play it, but it's going to become marginally more relevant, as you spend a land drop to draw a card a turn. Landstill will still suck. Drawing extra cards is great, until you realize that drawing extra cards is only good against control decks without cheap recursion. You can draw a counter each turn, but will you be forced to counter Moxen to keep your opponent's Goblin Welders from becoming active, Welding in Mindslaver, and ending the game for you?
GENIUS IDEA! Let's make a format that's already underplayed EVEN HARDER to get into!
The raise in price for Library is just what the format really doesn't need: more expensive cards, especially ones that can be played. I know that you probably have a few Libraries and want their value to increase, but pushing a format even further into isolation is ultimately bad for the format, and will damage the sustainability of the format, thus causing your "increased value" Libraries to become harder to trade, and thus, worth less.
1996 is gone. You can no longer plan on playing nothing but The Deck mirrors against other shitty players. Stop wishing for it.