The company will not be deleted if the director does not play for a long time as it simply drops the popularity back to zero after 90 days of the director being inactive. Companies that make zero dollars a day can still survive as long as it has company funds but once that runs out. Poof it is gone.
This is what is said in the company fund's section:
The daily income of the company will be put in to the company funds. The employees wages and costs of upgrades will be taken from the company funds. The director of the company has complete access to these funds. If the company funds go in to negative by a certain amount, the company will be destroyed and everything will be lost.
Environment is based on the size of the staff room and number of employees. If your rating drops it means you need a larger staff room to house your large number of employees, and/or you need to hire a Cleaner as stated in here: https://www.torn.com/wiki/Companies#Stocks_.26_Education_Affecting_Companies