Hello there,

first of all, let me apologize if this question is covered by the basic rules in English - it's not clear from the German instructions and I wasn't able to find clarification by scanning the forums.

So, anyways:

On some items the describtion states something like: "Use 2 movement points to make a knowledge check. If successful, draw two clues." So, say the investigator using such item has 5 movement points - would there be 3 left and the investigator allowed to move to another location, or would using such item terminate the movement phase for such a player?

Unless specifically stated, spending movement points does not end your movement. Thus, in your example, a 5 movement point character spending two of them for reading a Tome, still has 3 movement points to go wherever he wants. Please note that movement points are lost regardless of the result of the Lore (or whatelse) check!

Yep, as stated above, movement points act like currency, you can spend the required number to access the tome, skill, etc. then use the rest to move unless otherwise stated.

Also please note that the investigator in your example could spend his remaining movement points to read another tome if he wanted.