Yes, Samsung Galaxy A50 does have a 3.5 mm headphone jack.
No. Samsung Galaxy A50 does not have the LED notification light but it does have the Always-on display, so you can get notification alerts by any ways.
Galaxy A50 has a screen-to-body ratio of 91.6%.
Yes, Samsung Galaxy A50 does have fast charging support. It comes with 15W fast charger in the box. It takes about 30 minutes only to charge the mobile from 0% to 30%.
Yes, Galaxy A50 does have the NFC support.