Can i knock prone a foe with the shield mastery shove?

If a Knowledge Cleric have proficiency in knowledge skills, does Blessing of Knowledge…

Can I use a Staff of Frost as Quarterstaff?

Would it be over balanced to allow deep gnome the use of svirfneblin magic feat?

Lore Bard: are Magical Secrets & Additional Magical Secrets counted in the spells known chart?