Lots of Newbie questions, kind Kendokas!

1) Practicing Men yesterday the Motodachi (correct term?) got a little miffed, I think, that I didn’t pause in chudan before striking. Why is this? I mean, shouldn’t someone experienced be prepared for surprise? Or is it because that’s how the form is?
2) Are you supposed to put any strength into the Men or is it just a tap? It must be annoying as hell to be whacked by ignorant new people! If it is just a tap, would that have been enough with a real sword or is that just how its done in Kendo?
3) The Do strike – how do you manage to get the Shinai string horizontal, as I understood it should be on striking, without swooping the shinai as it comes down – is it just a twist at the last minute? Different students told me different things but the overall consensus was not to do a “baseball bat” type move.
4) What’s the correct way to measure your Men distance? When I just whent a little bit in from the tip of the Motodachi’s shinai I didn’t get anywhere near their Men, just annoying got them in the grill or the neck (oops!). I really had to go almost to the limit of the cutting edge to get anywhere, and couldn’t work out why as the Motodachi’s didn’t seem that much taller than me. From the way they kept stepping back I could tell most people manage with just the tip. I thought I was going crazy or had a particularly short shinai (I didn’t!) and felt v confused…
5) I stretched before the lesson and felt fine after, but now – 2 days later – I feel like a cripple (we had to do that massacring nasty jumping up & down suburi – haya? Hayashi?) – isn’t this weird to feel that so later afterwards? Or is it normal?

Many thanks!