Q/ Please find the 4 Taxes issues in the paragraph below and why?

Our clients Mel and Melvina Walsh are equal shareholders in a closely held C corporation. They have two children, Liv and BB. The children are attending college out of state on partial academic and athletic scholarships. The children have no plans next summer but hope to find an internship that will give them experience to perhaps one day take over the family business. Melvina has an antiques car collection and would like to purchase a warehouse in the area to store her collection; she has found a potential property, but it is about double what she would need for the cars, however the excess would be suitable for storing excess inventory for the business. The business has been doing well and has significant retained earnings. Mel has developed a hobby out of cataloging and restoring old automotive artwork that he sells at the various car shows he and Melvina travel to several time a year. The Walshs also own a second home they use as an Airbnb rental. They purchased the home several decades ago when they first married, and it has increased dramatically in value. They are getting bored with the rental activity and are not sure how long they will continue with it; they have been doing it for the last two years or so since they moved out of that house into their new home.