What means Dropped in mining?
It means that miner detected new block on network and need to start over
Can I mine from wallet and browser at the same time? Why miner does not use CPU heavily?
You can mine but on different addresses.
Mining on same address does not improve chances, because in every moment of time hash is same for same address.
It is planned to be easy mining, not impacting CPU or memory, so any device can mine coin.
Details about Elapsed Proof of Work, you can check in whitepaper document.