Core strength with closed kinetic chain activities using non-ballistic movements. Sauerman self-directed strain/counter-strain stretches of the multifidi (the paraspinal muscles of the lower and mid-back) with progressive use of gravity based resistance are a great initial approach to regaining function.
Yoga - done in a controlled way with a savvy, sports-minded instructor will do wonders for core strength, balance, tone and coordination, and prevention of future injuries. Yoga will also tune you in to any loss of protective reflexes that you may need to learn to respect as you return to normal activity. Some of the "systems" of Yoga are not flexible enough to account for the differences that a post-operative athlete brings to the studio. I would not try Bikram or similar rigid programs initially. Find a good guide at a private yoga studio who isn't going away soon - you'll pay more, but get much much more in that setting.
I would also advise against forming a dependent relationship with a chiropractor. Find one who supports and encourages all the active forms of rehabilitation I have discussed here - in fact print this off and ask for their guidance in enacting the steps that make sense for you.
If your chiropractor (or Physical Therapist) won't guide you in this way, I suggest finding an evidence-based provider who will. Some more experienced gym-based personal trainers may also feel comfortable with these concepts - but you would need to interview them closely for their actual experience with spine recovery. Otherwise, use the trainer as a resource for identifying which pieces of equipment can help you safely meet your goals, and rely on a guide with more medical/rehab training for specific answers.
You should probably consider putting the free weights away, and focus more on the activities listed above, plus consistent cardiovascular activities. Pick two of these that you like, and alternate them. Each activity puts a slightly different stress on the spine - remember that variety and movement are important to avoid reloading a healing disc or facet level:
!)Cycling (high seat, straight leg pump, handle bar extender with a mountain bike grip bar)
2)Swimming (start with a snorkel and fins if you have residual pain)
3)Elliptical trainer (vary the height and resistance to your tolerance, but don't be afraid to push your window here - not all central ache is warning of impending disc, and may just signal instability which requires weightbearing functional strengthening to improve and limit chronic pain). Combine this with active lower abdominal strenthening to your tolerance and ALWAYS use an active pelvic tilt to keep the LS region stable and supported during weight bearing exercise.
4)Fast walking is good - running may not be good until you are months (more than six, at least - but this is an opinion and not evidence based) - in EXCELLENT shoes or orthotics.
5)Review your occupational risk factors for recurrent back and disc disease - modify everything you can NOW. Don't screw up this chance to get back to and keep a "normal" life.
Anything that brings out lateralizing hip or leg pain is not good. You probably do have tethering scar tissues around the nerve root - as you become more active you may experience positional numbness out in the lower leg/ankle region - like a memory of where the pain was before. This will happen as you become more active periodically and is a normal process to go through as the nerve roots become mobile again (unless you have had a severe situation or a post-operative complication such as hematoma or infection which will possibly slow things down or not fully resolve). Continue to work through that, but stop if referred leg pain occurs.
Try supine lumbar extension after workouts if your have increased lower back pressure. Have someone provide counter-pressure for a gentle fulcrum to extend against onto your elbows gently and hold for up to 10 seconds. Some careful spine ossillations by a partner (trained directly by your Physical Therapist or Chiropractor in the correct technique and amount of pressure to apply) over the lower lumbar vetebra following these extensions can really free up workout stiffness for those of us who are post-laminectomy.
I had a bilateral L4-L5 lami about 14 years ago. You are on the right track if you are motivated to get moving and stay/become fit. Avoid weight creep as time goes by - that will add further stress load to your at-risk disk levels above or below the operative site.