Will to much vicks chest rub fumes in the air hurt my 7 month old?

Never for that young. I consider Vicks & similar products an archaic folk medicine with no redeeming qualities foe infants. The stink can and does aggravate a cough as an airborne irritant.The product itself is a throwback to pine pitch used in sweat lodges used by the Indians.It is fine for school age & older that can cough effectively, just not babies.
No usually not. Only in a very small enclosure with super high concentrations of vicks fumes would any problem occur. Use the rule that if the fumes are too noxious for you, they are for the baby.