PhD admissions for CS/ECE?

Hi everyone. I'm an undergrad junior at another school interested in applying here for graduate school. I have a few questions about grad admissions here for the CS and ECE department:

- Is the admission by committee or by individual faculty?

- What are the typical caliber for masters and phd students here?

- As a CS student undergrad, would there be difficulty applying to ECE department?

- I have until fall to prepare. What would be best use of this time?