Yep, there's a lot to work with in that strategy. I was personally trying out much the same with Strategist as one of the first picks as well, to give a second common source of GP birthed based GAs. Are you finding it's TOO powerful do you think? I'm not sure yet myself.
I had tried to use strategist as well, but it was quite a let down when so notices That you do not gain a free golden age each era, since you don't technically get a general, and all those great hunters didn't count either.
It is hard to say what is too powerful, it is indeed powerfull when it is ongoing, but flat bonuses are going to be quickly outpased by other bonuses when cities grow in size, so I don't think the golden age ones are too powerfull by themselves. The other point is that a lot of the golden age boosting traits also seem to need your golden ages if you do not play with pure traits, which makes stacking them much less powerfull.
Spiritual is kind of the key that make this engine go off, since it allows you to get a lot of these golden ages in the periode where the flat bonuses are very powerfull. Without those the bonuses to golden ages from glorious can still be activated early for the captured fire, but there wouldn't be more golden ages for quite a while meaning it wouldn't be too much trouble balance wise, perhaps it could even be considered a poor choice.
What it really comes down to is the uptime for golden ages, and how big those flat bonuses are in relation to what you could have gotten from other traits. If the golden age uptime ends up with less than 25% then the flat bonuses would be inferior to other traits, you probably need an uptime closer to +50% to see a singnificant unbalancing effect. This is why I termed it mainly as a tempo pick, which also provide some effect later, since it mainly allow you to go through some key parts of the game faster if you play it just right, which you then need to turn into an advantage long term.
It is at least an alternative to slave bonus stacking, but I guess slave bonus stacking is more generally powerfull, though it does require you to throw a lot more traits at it and does fall off much more brutally late in the game ( though do remember that you can easily decide a game much before then, if you have 2/3'rds of the map by then and an era or 2;in advantage, then it doesn't really matter as long as it doesn't put you on the brink of collapse).
If you want to fix something, I would mainly suggest to change the form of bonuses from powerfull golden ages (the main problem is getting large flat bonuses very early) or spread the bonuses over more traits that also do some other nice things, and are still stackable, such that you don't get so much if the needed power with just 2 traits (which is the reason the timing works). Personally I don't think it is quite needed to need it right now, and I play with generally longer golden ages, since I found them otherwise quite short in the default setup on the faster game speeds (maybe 1-3 techs long).