tech issues with photos i uploaded

First question: moderators don't have the time to post lengthy explanations why they rejected this or that picture. They give a hint, for you to look at your picture critically and to check what could lead to a rejection. If you do not find the reason, post it here and we will analyze the picture for you. After 10 rejections you will know where to look before uploading and how to analyze the rejected picture. It's a learning curve. 

You could also read this manual:

If you are new to stock, you should consider these resources: https://helpx.adobe.com/stock/contributor/tutorials.html
Please read the contributor user manual for more information on Adobe stock contributions: https://helpx.adobe.com/stock/contributor/user-guide.html
See here for rejection reasons: https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
and especially quality and technical issues: https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html

Your second question: You see only a preview of your picture, if you, as a buyer buy a picture, you get exactly what has been uploaded. So upload high quality pictures, because buyers expect those.