Help me clean up my task list

hello everyone, i just wanted to post a task-list that I wanted cleaned up a bit. it does everything that i want, but it seems to be a bit buggy and i thought i could get some help.
--when i click the "clear completed" button, it only clears about 70% of the completed. I then have to click clear 2 more times to get rid of the rest.
--i have to have my G1 cell filled in the "archived tasks" sheet filled with something in order for the archived tasks to insert the completed tasks in a new row.
--i would like the completed tasks to be inserted newest at the top and then oldest at the bottom instead of vice versa.
-- when a new row is inserted, id like for the row to clear the formatting of weird stuff like the bolding, grey fill etc, in a simple way rather then telling excel step by step to "1. change color of cell, 2. unbold 3. borders" etc...

i worked on this forever as its really hard to piece together code that is kinda what you need, but not really. but id also like to just see how it could have been done neatly.

any help would be great!

thanks for the help. it looks good but the issue is that i can clear it the first time it clears perfectly; but the second time it overwrites the old archived tasks. ostensibly it would push down the old tasks and archive the newer tasks on the top... its a better method though of clearing the old tasks for sure, so I will see if I can modify!