Businessperson incurs the following § 162 business deductions. To what extent does § 274 limit their deductibility?

B takes client to lunch and a ballgame and, to Client’s dismay, discusses business most of the time.
B takes an education course in another town incurring transportation, meals, and lodging expenses.
B purchases gifts costing $55 each for significant clients.
B purchases airplane which is used 60% of the time for business travel and 40% of the time for client entertainment.
B provides employees with qualified parking which is excluded from their gross income under § 132(a)(5).