1) Yes.
ActiveForm -> Controller -> UploadedFile - standard in Yii
Via CURL from another server
2) Yes.
ImageOptimizer\OptimizerFactory + Eventviva\ImageResize
GD or ImageMagic can be used also.
Relevant Skills and Experience
Main: PHP, Yii2, REST, JS, Git, MySQL
Additional: Node.js, Angular, CentOS, Ubuntu, PostgreSQL, Redis
Proposed Milestones
$555 USD - mock