1- Dramatic neccessity, scheming of Palpatine, etc.
2- Better if the Jedi find him. It worked rather well into Sidious' favor, then if he had simply raised Anakin as a Sith he would be overthrown and the Sith ideal might have faltered. Better to have Anakin in the jedi's ranks and tempt him from there.
Re: Two Questions
Originally posted by Darth_Glentract
First, if the Jedi Order knew of the attack on Naboo, why didn't they send a team of Jedi to liberate the planet?
Yes, number one is very simple- the Jedi had no authority to. People keep forgetting that the Jedi are not dictators, they are servants. Whilst the Senate was still debating the matter the Jedi could do nothing- other than keep QGJ on a mission of protecting the Queen in order to try and draw out the Sith.