Hey Kamskun, great start on the workbook there!

I agree with you that for starters, it's good to focus on one method first for a while, and see how it goes. My suggestion would be a DILD, combined with WBTB. The waking up early then going back to sleep sets you up really well for a lucid dream, such as a DILD. However, if you're finding yourself kinda drifting in and out of sleep and having dreamlike scenes appear (the "screenshots" you mentioned), you could opt for a DEILD instead.

As far as the issues with your memory, of course keeping a dream journal will help improve dream recall a ton. And folks who keep a waking journal as well have reported success in not only improving waking life memories, but an increased ability to remember goals once in the lucid dream itself.

Hope this clears some stuff up for ya