Having a high number of applications in a short period of time will slightly decrease one’s credit score. Staying at or below 1-2 per year usually hasn’t swing mine more than a few of points. Even with a high number of inquiries, this factor only accounts for 10% of the most commonly used FICO score.

Debt burden and length of credit history are, together, 45% of someone’s score, and these are both improved by having a lot of old unused credit cards.

https://en.m.wikipedia.org/wiki/Credit_score_in_the_United_S...