hm... i think that "Should I decide to to use your commission for the aforementioned purposes, I will contact you in advance to let you know in case you later decide to purchase exclusive rights to the work" is already covered by the sentences preceding it. you have already made it clear what your expectations are. brevity is important.

it feels like "I reserve the right to recycle any sketches or preparatory works rejected by the client for other commissions or personal works" should be in the artist's rights section though.

the rest of it seems long, but i'm not really sure how to condense it because i don't know exactly what is most important to you. to give an example of a tos i find appealing in length, i commented on germanchoclates' up there. slightly longer but not too wordy also is celestinaketzia's upthread a ways. i just heavily recommend condensing where at all possible to make things easier on people who want to throw money at you.