If I'm reading this right(and looking at the final picture), the beam itself is sagging. It may have reached an equilibrium point, and simply jacking up an reattaching it will fix it. But you'll still have a bowed beam.
My inclination is, a properly built beam should be able to span that distance and hold the weight without sagging. I have smaller, longer glulams spanning my basement, supporting two stories. But maybe someone who knows a bit more about structural engineering will chime in.
If you want to create one yourself, I would use like 3 2x12's laminated vertically. Boards are much stronger vertically oriented than horizontally. Think floor joists or door/window headers.
All loads on beams / columns matter. So, if you are adding beams (loads) to existing beams, you are right to worry about its affect. However, there are three things in your favor: 1) everything is designed with a "safety factor", 2) residential design is way-over designed, and 3) beams are designed to fail in tension.
1) Structural design has "Working Stress" and "Ultimate Stress". Ultimate stress (failure) is about 150-180% more than working stress (what we design beams, columns, etc. to).
2) Residential design is largely done by non-professionals (architects and structural engineers). So, "what is commonly used" in residential construction is grossly over sized.
3) Beams are designed (design formulas used) to fail in tension. That way, we'll see cracks and presumably investigate, rather than fail by compression, which will fail with a bang...and have a disaster.
So, back to your question, yes, there is a way to determine how much weight can be added to a beam, how big holes (and how many holes) can safely be drilled into a beam, etc. However, unless you're "doubling the load" or excessively drilling an existing beam (1 connector is not excessive), then I think your safe.
You can destroy a concrete beam quicker than steel or wood beams. When drilling the concrete beam, you'll know quickly if it's a poured-in-place beam or a steel beam encased in concrete. In fact, you may not be able to drill through the steel/concrete beam. So, rather than "mess with the concrete beam", why not design a "saddle" to fit over the beam and support your new added beam and lights.
If you decide to proceed with drilling the concrete beam, I'd recommend you contact an architect or structural engineer (not a CIVIL engineer.)
Best Answer
I'm going to be contrary. Looking at the Weyerhaeuser documentation ( https://www.weyerhaeuser.com/woodproducts/document-library/document_library_detail/tj-9000/ ) PG 26 shows you the allowable hole locations.
For parallam beams, it's in the center third of the depth and center third of the span. Your holes violate both of those conditions. They don't even mention drilling from the bottom or top, but that's probably a no-go as well. From the same page:
I think you need to have your engineer look at this. The fix might be as simple as the engineer writing a letter accepting it as is.