Validation of purity and quantity of gRNA in your samples are best done using spectrophotometry methods(e.g Nanodrop)..I suppose the DNAse I treatment should take place before the elution of your RNA samples from the columns as this is crucial to its purity.This question will be better answered if you mention why the DNAse I treatment was excluded for some and included for others.
you might have sheared mRNA and however for best RNA QC you should run Qiaxcel or Bioanalyzer and get RNA integrity number between 7 to 9 this is ratio b/w 18s/28s ...looing to your gel... ur purufucation has not gone that well... again if your plan is for rtpcr try to make cDNA and try PCr you might get results.. hwoever for NGS this is not good... and joke..nanodrop might not give you quality but quantity... we need RIS or RIN values
I think you can use your samples for cDNA synthesis. If you cant get satisfactory results from the cDNA reaction, you can try to gradually increase temple amount, but i m pretty sure u will have your cDNA.