You can only do these things on your turn unless a card specifically states otherwise
I just want to play fair and get rid of these doubts
Several reasons: English cards were the global product
Boring, but Practical: "Book of Verse" only offers a pretty minor skill bonus, but the asset itself is cheap, its uses are easy to restore, is slotless (unlike most Tome assets, which usually take an hand to read/use) and can occasionally offer him draw
The card wasn't purchased at the Whitby store, but the person who made the life-changing pull is the cousin of a frequent customer
Now, let's give it Prowess and let you make copies of it in the late game I'd say this is one hard-hitting horse, and this is a kicked Burst Lightning's best friend