Based on the post above by dcw123, I compiled a concise summary with some good-looking images.
Lara's limitations: summary
Lara can clear a gap...
...two squares wide, with a standing jump:
...three squares wide, with a running jump:
Remark: in both cases, the destination ledge can be one click above the ledge she is jumping from.
Lara can reach an edge...
...seven clicks above her, with a straight up jump:
...six clicks above her, with a standing jump:
...six clicks above her, with a running jump, if the edge is after the first square:
...five clicks above her, with a running jump, if the edge is after the second square:
Lara will run out of air after swimming 87.5 squares:
Note: if she swims in a non-straight line that figure will be reduced.
Lara can sprint before getting tired ten squares:
After running off a ledge, Lara can cover...
...one square, if she was at the edge:
...one and a half square, if she was away from the edge:
...almost three squares, if she was sprinting:
Lara will die after falling...
...21 clicks, if she hanged off the edge:
...18 clicks, if she ran off the edge:
...17 clicks, if she jumped off the edge:
Lara can aim at an enemy away from her eight squares: