Someone who hides their emotions is often referred to as "emotionally guarded" or "reserved." They may also be described as having a stoic or poker face.
Someone who hides behind a hypothetical situation can be called an "armchair critic." This term refers to someone who criticizes or provides opinions from a safe and hypothetical position without actually taking any real action or responsibility.
Chemist
customer
Arch
a tanner
Hollandophile or nederlandophile
Crazy.
A person who does things for others may be an assistant or a helper.
adventurous
A Philhellene.
frivolous