2 and 3) example: u got 10 coins. one minted block is about 0.8 coins. interest is now 35% for solo staking and 65% for masternode per year. so your 10 coins give 3,5 coins per year. so you will find an average of 4,375 blocks per year. That means, if your wallet is 24/7 online and staking, u will find a block every 2-3 Month.
As this blockfinding is based on luck, it could be possible, that u will find 2 blocks in one month or zero blocks in a half year.