1) is it best to use shamash to light candles or can this be lit last by a match or other flame that one lights the other candles with?
2) can one tilt and adjust lights after 30 min and add the leftover oil from previous days at this time?
1) Both options are fine. Although the Rema mentions that the custom is to use the shamash to light the candles, this is not by way of obligation, and it is fine to use a different candle, and tolight the shamash after the candles.
2) This is fine. In principle it is even permitted to put out the flame after the half-hour period has elapsed (though one must stipulate that one will do so before actually lighting), and therefore there is certainly no problem in adjustment and adding oil. Moreover, I don’t see a problem of doing so even within the half hour period, provided there was sufficient oil to begin with.