Effectively yes. Investing in themselves as opposed to other opportunities.

It’s often a market buy signal, however the market prices it in pretty quickly. It also means less shares for sale short term, and can drive prices up - however often the shares they buy back are not via public exchanges and instead private off-market deals.

No its the opposite. The company has a pile of money they could use to invest in new endeavors, but instead of doing that they’re saying “we dont have anything worthwhile to do with this money, so well give it back to shareholders.”