The first is a triggered ability: "When this permanent enters the battlefield, target player may search their library for a card named [name], reveal it, put it into their hand, then shuffle." Note that the target player searches their library (which may be affected by effects such as that of Stranglehold) and that the card they find is revealed, even though these words aren't included in the ability's reminder text
If it changes zones, it will either cease to exist (if it's a token) or cease to be a copy (if it's a nontoken permanent), and so you won't be able to cast it as an Adventure
When you turn Boltbender face up, you can redirect any number of spells and abilities to new targets
Instead, we got a limited-only removal spell that transforms into an Elf that cares about lands
The most played cards are usually worth more than others of similar rarities