Mixing Dubstep

I've recently gotten into DJing and so far, it's mainly been dubstep. A few questions I have as a beginner:

1. When you want to mix in a song that is a bit faster, (e.g. 140 to 145) what is the best way to mix into the 2nd track?

2. Where is the best mixing point for dubstep when they are the same BPM?

3. Are hot cues really necessary? I'll occasionally mix on my friend's setup where I don't have hot cues. Should I try to setup hotcues on the fly while the track is playing out or is there a better way to find the right mixing point?

Any other tips anyone might have would be greatly appreciated!