There's a number of ways to work it and still be okay for recovery. Optimally I'd like you only do 1 day per week of hard conditioning with one of the following protocols on a day off (like Saturday at the end of a training week with another recovery day coming on Sunday):
-7 rounds x 20s ALL OUT effort:1:40s active rest, 10 minute cool down
-12 100' prowler sprints on the minute every minute
- any cardio modality x 10s on, 50s rest, 12 s on, 48s rest, 15s on, 45s rest, 20s on, 40s rest x repeat 3 total times and 10 minute cool down.
The boxing would likely be too much volume to incorporate into a SS program. Sprints would be okay, if you are decent at sprinting, otherwise the added stress on the body from the forces and rapid contractions might depress your squat from progressing as quickly, which is one of the goals in the SS program. I'd also bump up your protein to 225g, then add more carbs and fat to gain weight. You'll likely be your strongest at 195-220lbs so we need to get closer to there rather than 160-175.