All very good questions. The following responses are based on what I’m reading from a Taiwan driving handbook which I am currently holding in my hands. Please note that I am NOT reading from the law books, which take precedence over the handbook.
A single solid yellow line in the middle of the road is not mentioned anywhere in the driving handbook, nor have I seen it anywhere in Taiwan. This also does not exist in the US or the UK, but does in Canada.
EDIT: Regarding solid double yellow lines in the middle of the road, it is confirmed in another post that it is illegal to cross them, even when making left turns into a driveway.
Similar to the US, a broken white line in the middle of the road separates lanes of traffic traveling in the same direction on a one-way road. Note that this is different from the UK where single broken white lines can signify different things depending on the length of the dashes.
A red line along the edge of the road means “no stopping or parking”, whereas a yellow line means “no parking”. Note that picking up and dropping off passengers is permitted in the latter, while not in the former.
Never.
However, if you have a separate green right arrow at a red light, you may turn right after yielding to all other traffic (including oncoming traffic turning left, which is different from the US).
Also note that a green right arrow is different from a green left arrow, in that the latter signifies a protected left turn where you have the right of way. In the former, you have to yield.
Lanes are categorized into the following.
Slow lane: For scooters and bicycles traveling slowly, and for cars about to make a right turn, about to park, or just leaving from a parking spot. All other cars are prohibited from traveling in this lane. The slow lane is separated from the fast lanes by a single solid 10cm-wide white line.
Fast lanes: Normal driving lanes for cars, motorcycles, scooters, bicycles, and all other types of vehicles. Fast lanes are separated from one another by a single white dashed line.
The left-most (or inner-most) fast lane on regular surface roads are usually meant for traffic going faster, and for traffic about to turn left. Note that many inner-most fast lanes have a “no scooter or bicycle” restriction, which is marked by yellow Chinese words painted on the street.