Can the government prove specific intent of 'use' without minor testimony, relying solely on circumstantial evidence and images, in violation of federal child exploitation statutes?

I. CAN THE GOVERNMENT PROVE THE SPECIFIC INTENT OF "USE" "FOR THE PURPOSE" WITHOUT THE MINORS TESTIFYING(direct evidence), OR CIRCUMSTANTIAL EVIDENCE(hot line tip, captions on the videos, etc.), WITH NOTHING MORE THAN JUST THE IMAGES THEMSELVES IN VIOLATION OF 18 U.S.C. §2251(a), and 18 U.S.C. §2256(2)(A)(v)? IIDOES A FEDERAL JUDGE HAVE TO CONDUCT A THOROUGH DIALOGUE ON THE RECORD TO MAKE SURE A DEFENDANT, SHACKLED OR NOT, PRO_SE OR REPRESENTED, KNOWINGLY AND VOLUNTARILY WAIVE THE RIGHT TO TESTIFY, AND DOES THE SUFFICIENCY OF THE EVIDENCE WHICH CAME ABOUT AFTER ALL THE EVIDENCE OVERRIDES THE CONSTITUTIONAL VIOLATION THAT BEGAN AT THE START OF THE TRIAL? III.WAS THE PETITIONERS SENTENCE MISCALCULATED AND UNREASONABLE DUE TO THE JUDGE BEING VINDICTIVE AND NOT STRAYING FROM THE "DRACONIAN MANDATE" OF THE FEENEY AMENDMENT IBILL? IV