BP9,

Thanks for including the photo - that is helpful. Your hand postion looks to be in good shape from that picture. Your 30-second-hold plan is excellent for stretching and strengthening your fingers, developing their aim and their sense of 'feel' for the fretboard.

Keep in mind that the ultimate goal in learning to make music on the guitar is the FLOW of the music. Getting from chord-to-chord, or from note-to-note ON TIME, and with good confident clarity. You will need finger strength and flexibility for that, but you will also need to build in confident certainty in your chord-placement, and the ability to get the timing spot on. 

aliasmaximus gives excellent advice in the above reply to your question when they say:  "I think that you would get more bang for your buck if instead of holding a chord for 30 seconds, you instead just try to "grab" the chord (at a comfortable speed), then plucking the strings one at a time to isolate any fingers that are out of position. Then immediately release and grab again - over and over. You'll acquire muscle memory much quicker that way."

Great work so far - keep it up, and have fun!

-Lisa