Air carrier Flight Attendant reported a passenger misconduct and an unrelated issue of a passenger who allegedly checked a bag with lithium battery. The Captain was notified of both issues with no additional information provided.

Narrative

Date: ZZZ to ZZZ1Position: B-FA (Flight Attendant)During boarding; passenger on my flight was upset about having to check her bags because she was traveling internationally to ZZZZ. She approached me in the back and insisted there was space for her bag and that she wanted to bring it on board. I suggested she speak to the speak to the A-FA in the front and see if it was possible. Once she went back to the front and saw the ramp agent threw her bag down; she approached me again and began yelling at me demanding an explanation for the other flight attendants refusal. I explained that it's protocol for any tagged bag to be sent to cargo. She returned to her seat after our discussion. It wasn't until we were inflight and I was doing beverage service that I noticed she was filling out a complaint form to company. I saw her writing but I continued with my duties and asked if she wanted anything to drink or a snack. She looked at me; noted my name and requested water. After I finished service; I started to reorganize my galley for the next flight. However; I heard several overhead bins opening simultaneously which concerned me. I discovered that the passenger had opened them and was taking photos of all the empty bins. I needed to prioritize securing my galley so I focused on the safety in the back. Once I finished; I checked to see if the passenger was still standing in the aisle but she had returned to her seat. I called the A-FA to inform her about the passengers actions and we both agreed to notify the Captain. The A-FA also mentioned another issue involving a different passenger who had allegedly checked a bag containing lithium batteries and medication. I then updated the Captain about the upset passenger regarding her checked bag.