the quality of the board really does not matter when you're at your level. you won't be able to tell the difference except to feel that stiffer boards will be harder for you to control.
for going down the mountain and avoiding rentals what you have is fine. it is on the short side for your weight, so if you're riding on a powder day you may have to play around with your stance - in powder you may have to set it back so that your tail is short, nose is longer.
as long as the length doesn't become an issue for you that board will last you several (many) years of 4-5 days per year. eventually when you can ride more aggressively you may find that you need a better board to keep up with you, but you'll know it when you're there.