Let the show begin

I have tried to read the da-rulez and I figured I had invite critique?
http://madmodder.net/index.php?topic=2527.0"Also bear in mind, if you ask for comments or critiques... you may not like what you hear. But thats also what this board is about... without constructive criticism, someone may not finish a project or worse yet, get hurt."
I don't have a very thick skin, but luckily I don't understand all the fines either. And please bear with me: I have dyslexia on all languages, I read fast and understand most of it, it's mostly writing: I'll put letters slightly on wrong order or use "close" letters and I even don't see it. My speciality is to "skip" few important letters every now and then...I'm trying speller, but it gives me ridiculous suggestions - normally opposite I want.
Anyway everyone have to start somewhere if someone sees that I'm making something completely wrong I'm happy to be corrected.
The trouble I had was manual circular milling - first time I ever tried but there is probably a better way of doing it. In the bright side:
* It workked, although it was slow, but it was a deep hole and I could not run mill fast enough
* End mill stayed shar and it was very cool (immersed on coolant all the time)
then again:
* Should I have used an slotdrill? I used four flute end mill that has a limited plunge ability. I used very gentle ramp down (slow Z with left hand, while winding willies out of rotab w/right hand.
* Probably should have gone bigger and produced more swarf, this "deep", would have improved D/x
* feeds are hard to handle well manually, on the other hand I felt all the time how the cutter was cutting
* Made a bad choice with coolant - heard it used, I had to have a try. Next time I'll rig shopvack with narow spout
Maybe I should have tried something completely different? I could not see myself using holesaw, I don't thik chips would have come up and I dont like to peck drill on kneemill without pinole. On bright side: I would look soon like govenor of California when he was young.
But that was yesterday. Today I have to consider arms.
If I understgand right arms:
* better be softer than piece to be turned
* Should not easily weld on that piece - this would exclude most aluminiums
I have 10*10mm square brass rod and then probably a bronze plate that is 8-9 mm thick....from junk-yard (alhough they don't call it that anymore they all are recylcle something). Both feel smallish, I'll probably lash up someting temporary and fix ita lter when I'll get something better. Now How do I keep witnesmarks when I take it off the rotab?
Anything I should know about the arms. Most builders don't go into very many details here on materials and shapes. V-on the end and everyting reasonable square? That's it?
THank you,
Pekka