8) I generally prefer an assistant to hold diffusion panels unless they're huge! For modest sized diffusers, I use this product from Photoflex:
http://www.bhphotovideo.com/c/product/42107-REG/Photoflex_DL_BHOLDER_Telescopic_Litedisc_Holder.html
These are GREAT quality, but you may find low cost alternatives on eBay. I destroyed a number of poorly engineered cheapies before spending on the well made Photoflex holders.
If I'm using a 6 foot/2 meter diffuser, clamping it to a rod between two lightstands works fine if it needs to be vertical. Check these Manfrotto products out to see what I mean. You may be able to invent a low cost DIY version.
http://www.bhphotovideo.com/c/product/5217-REG/Manfrotto_2983_2983_Adjustable_Background_Holder.html
http://www.bhphotovideo.com/c/product/648381-REG/Manfrotto_1314B_Background_Support_System.html
If it needs to be horizontal or angled, set up two more lightstands with a rod between them, set up the suitable heights and clamp your diffuser on. Remember if you're working outdoors, these things catch the slightest gust of wind.
On the subject of DIY, I have seen very effective, easily assembled and dismantled frames for diffusers made from a stiff grade of electrical conduit, incorporating the compatible 90 degree corners. Depending on the required size, incorporate one or two cross braces. Create triangular pockets at each corner of your diffusion fabric, and stretch it onto the frame.
-pw