timber door

About to paint some external timber door and window frames. One is showing lot of surface cracks as can be seen in photos. Would sanding alone be sufficient for this or should I use some wood filler (e.g toupret or similar ) first and then sand. The cracks are all over so if I use a filler...

Hi have an internal and externak timber doors that keeps swelling especially during the rainy seasons and make it difficult to open or close. I planed the edge where it was sticking and it was fine for a while but appears to have swelled again due to all rainy weather. Whats the best way to...