Yep, keeping within a margin of balanced is fine. One of the reasons for rebalancing with deposits/dividends rather than sales is that sales might trigger capital gains tax. In my country, there is no capital gains for buy-and-hold portfolios. Although the law allows sales to rebalance, it's on you to keep documentation, and you might be asked questions. So, much easier to rebalance with deposits/dividends.
Yes. Have to find and do what works for you, and within guidelines presented to you.