disguise yourself: Jeroboam knew his wrongdoing kept him from approaching God's prophet. He understood that the prophet who foretold his rise to Israel's throne could also predict the child's future and possibly ask for God's help.
Shiloh was destroyed by the Philistines during Eli's time (1 Samuel 4). Before that, the tabernacle was there (Joshua 18:1; 1 Samuel 1:3). A small community lived there again, but the area stayed mostly undeveloped during the divided kingdom.