Learn English – What do we call a wife who “cheats” on her husband (without having sex with the other person)

Besides previously suggested terms also consider pet (“To stroke or fondle (another person) amorously”), although that may have more-amorous overtones than you desire; and pat (“To (gently) tap the flat of one's hand on a person or thing”), as suggested by Trish Rempel in a comment.

You write, “I thought "goose" would be suitable, but Wiktionary says that's for sharply poking or pinching, which isn't the case here.” Yes, wiktionary says “(slang) To sharply poke or pinch someone's buttocks. Derived from a goose's inclination to bite at a retreating intruder's hindquarters.” This is in accord with FumbleFingers's remark, “Goose is usually equally unwanted, but doesn't always carry such strong sexual overtones [as groping]” and with J.R.'s, “A goose is pinch or grab, usually surprising and unexpected; whether or not it's welcomed or unwanted would depend on who was doing it, and the relationship between the gooser and the goosed.”

You write, “Would "fondle" or "caress" be suitable, or is that more associated with sex?” For fondle wiktionary offers two senses, “To touch or stroke lovingly [eg] Mothers fondle their babies” and “To grasp [eg] The lovers fondled each other”. I've always thought of fondle in the former sense, and was unaware of its “To grasp” sense until now, so would not have assigned such overt sexual overtones to it. Wiktionary also offers several senses for caress, including “To touch or kiss lovingly; to fondle [eg] She loves being caressed by her boyfriend” and “To show and act on deep closeness shared with another person”. I think caress in the latter sense probably is the best word here.

Talk that is pompous but not concrete is vacuous. ( It is pumped up but not solid, so it is empty—or full of air like a balloon.)

If he uses magnificent words, he may be grandiloquent http://www.thesaurus.com/browse/grandiloquent —and still vacuous.

If he makes unsubstantiated, fallacious arguments that only appear to have any substance, they are specious. http://i.word.com/idictionary/specious

If he makes big, vague promises without delivering any workable plans, he might be said to be

• all sizzle and no steak

http://www.learn-english-today.com/idioms/idiom-categories/descp-people/descr-pp1.html