It would have been the proper thing to do to post your questions on the impressioning thread as then its all together, what youve done here is made a new thread that has already got some good info on it and yet the two cant be read together,
Please think about this when making new threads,
As regards your issues, im a little hesitant in posting a reply foir the above reasons, i would like my reply to your question in the impressioning thread so it may help others but thers not a lot we can do about that now

I dont think you understand impressioning much and that could have been addressed better on the other thread, i dont mean to go on but it annoys me,
When a pin is at the correct height it is now resting on the cut in the key and has no top pin pressing on it,
Turning the key a bit doesnt catch the pin on the casement either when its at the correct height so theres simply no marks made,
Now that said, if your not useing decent magnfiacation or got great sight then you can easily miss a no mark and file again or you can more likely cut to deep with the file on the last strokes to depth,
What this does is to drop the pin belwo shear which obviously lets the top pin drop below shear and you again start to get marks,
Miss the marks and youll end up with a bumpkey,
You dont get marks on every spacing no matter how hard you tension the lock, its the same as picking, you find the binding pin and pick that, some locks get more than one binding pin so you let of the tension the differance is in impressioning you can get marks from all those pins and then file them al a little but as for a lock giving a mark for every pin in one go i dont think its easily possable,
That all said im no expert on impressioning and still need to practice a lot on it myself, i used a box of 50 keys last month playing around and tried every idea i could think of and the only way i found to dspeed the process up is to use space and depth keys and cut to the next height on each mark but it doesnt alays work if indeed you miss the mark,
The idea of dropping down the number of pins is a supurb one that was said to me a while ago by someone i know as the best impressioner i know and it works well, i started with 3 pins myself and got a key first time whereby i couldnt on the same lock witht he extra 2 pins in, then i went to 4 then the 5 and got that in the end, good light and magnifacation is a must,
As regards files, triangle files with flat on are ok if they work on the lock you want it for but most do not have flat bottom cuts so i think if you stick to the norm and do as everyone else suggests you will not veer from the path to much,
When impressioning i find that everyone including me becomes an inventer and decides that they know better of can work an easier technique out but al it does is to hold up progress and in some cases mean you will never actually get it down right,
Get a good clamp, a good light, a good magnifier and a good file and just practice the exact methods described in the impressioning thread, trying to come up with short cuts etc before you can do it properly is only stepping you back, theres no easy ways to do it,
If you are after videos etc then its a bit thin on the ground because present video quality doesnt really give out the detail needed to see the marks on film, the best solution i can offer is to look up olivers impressioning book as it looks amazing its just a shame he hasnt replied to my last email to him asking where to send my money to get my own copy so i suggest you dont hold your breath on trying to get hold of one from him, i see Chris Belcher has it listed on his site so when he gets the english version in ill buy it off him instead,
I hope this has been some use, im no expert and can only repeat what ive been told on this, i didnt mean to come across so harsh at the begining but i pull my hair out over threads like this that should and could have simply been posted on the actual thread made for this subject, now we have a few posts with good info on them that are never gogin to be seen by those useing the proper thread to read up on the technique so i guess they will do the same and post another new thread for a question,