Does it have a real set of leaves yet? The ones that look like marijuana leaves?
And if the round leaves are yellowing, its normal.
But by looking at your pics, I would say its your soil. Looks really bunched up and... weird. What kind are you using?
If your PH it off it might stress it a little and your nutrient intake wont be as good since nutrients have a preferred level.
But 7.3 isnt THAT bad, but if you can lower it then go for it.
I doubt it'll make much difference, best bet is to use bug spray.
I had a fly trap once, it didnt catch a damn thing! And a venus fly trap requires a lot of humidity so there would be a dome around it 24/7.