Beginner's Questions in Splinterlands

Hello guys!

I joined the SPLINTERLANDS game a few days ago and I'm fascinated trying to understand the dynamics of the entire HIVE ecosystem and I've already discovered a lot of new and interesting things these past few days.

In the first days I learned about cards, about battles, about abilities, how to build the deck and started doing daily quests.

In this second moment I'm acquiring some cards to help in my battles, increase my power, rent to other people and also to increase my points in the daily airdrop and increase the SPS stake.

But even looking for information in the posts I still don't understand some things and I would like to ask a more experienced community for help:

1 - Why are there so many potions in the chests? How can I use it? Is it just buying the packs?

2 - Why is my SPS balance not shared with my other wallets? I thought it was automatic, one wallet for the entire HIVE. But it seems to me that each site (peakd.com, splintertalk.io, etc) has its own wallet with the respective balances.

3 - From what I understand to vote on splintertalk content and win SPTs, it is necessary to have SPTs in stake correct? In which broker would it be possible to buy SPTs for those who have nothing and would like to enjoy the posts of others? Or is it just posting content to earn the first SPTs?

If someone can help me with these questions it will be very important and maybe help other people who have the same doubts.

If you want to start playing and enter this fascinating world follow my reference link on Splinterlands > > https://splinterlands.com?ref=maisrenato

Good luck to everyone!!!