Every hand you can be dealt, on one grid. Pairs run down the diagonal, suited hands sit above it, offsuit below.
Pick a seat. The highlighted hands are a sound opening range from that position — tight under the gun, wide on the button, because the later you act the more often everyone has already folded.
The button opens roughly four times as many hands as the first seat, and it is not because the cards are better. Acting last means you see what everybody does before you commit, and that information is worth more than the gap between ace-jack and ace-queen.
Every other seat on the chart is choosing whether to open. The big blind is choosing whether to defend against somebody who already has. You are getting a discount — part of your money is already in — so you continue with far more hands than you would ever open.
A chart tells you what to do before anybody acts. It has nothing to say about the hand after that, and following one rigidly against a table that has noticed is worse than playing badly but unpredictably.
169 distinct hands, but 1,326 actual combinations — pairs come in 6, suited hands in 4 and offsuit in 12. Percentages here are weighted by combinations.
At a full table, from the first seat, yes more often than not. It plays badly against the range that continues against you, and there are eight players still to act.
No. It is a common, solid set of opening ranges — a sane starting point rather than a claim of optimality.