The 28-year-old, who is allowed to play in the Challenge Tour event as his suspension only covers PGA tournaments, recovered from being three over after just four holes to sign for a level-par 71.
Kerr has made just one other competitive appearance since the second stage of the European Tour's qualifying school last autumn and has found little time to fit in the practice he needs since starting as a PGA trainee at Marriott Dalmahoy earlier in the year.
But, despite feeling nervous, he bounced back well from his poor start to finish the opening day just six shots off the early pace, set by Swede Magnus Carlsson.
"I'm only here really to see what my game is like and, to be honest, I don't expect to make the cut," said Kerr. "Before Sunday I'd worked 70 hours in nine days and it's impossible to do that and compete against the guys on the Challenge Tour.
"I was nervous at the start and wondered what I was doing here after dropping three shots in the first four holes, but 71 wasn't bad in the end even though I didn't play all that well."
Kerr, who tied for fourth in last year's Northern Open over the Aviemore course, is determined to put the events that led to him being banned along with David Orr, the Scottish PGA champion, in the past.
"It's over and done with," he said. "I'm now three months into my training at Dalmahoy and I'd be silly not to get my PGA qualification as it will be something to fall back on."
Defending champion Jamie McLeary, who is attached to the Kirknewton club and lives just outside Bonnyrigg, also opened with a 71.
"If that's my bad round out the way I'll be more than happy," said McLeary, who felt he was ticking along nicely until running up a bogey-6 at the long 13th.
He repaired the damage straight away with a birdie at the 14th before picking up another shot at the 17th.
Elliot Saltman led the Lothians contingent after an opening 69.
Raymond Russell, the top Scot on the Challenge Tour Order of Merit coming into the event, had a 72.
Lee Harper and Lloyd Saltman also finished the day on one over, the latter admitting his dinner last night would taste better on the back of a 25-foot birdie putt at the closing hole.
"I'm playing really nice from tee to green and if I can start holing some putts there's a good score waiting for me," he said.
Among the later starters on the opening day, Shaun McAllister and John Gallagher shot 74 and 75 respectively.