Move the click to Ask in to the header rather than the sidebar, then move the welcome to the sidebar and change the icons to upward arrows. - On iPad your Ask a Question button is at the bottom of the page, not ideal. Or even combine them both into the header, (Ask a Question first)
Favicon - You need one that isn't NodeBBs. Not a huge issue, but when you decide on a logo, make a favicon and upload it into your public folder of nodebb, or if the ACP favicon bit works, use that.
Add this to your Customise CSS in your ACP.
I was going to say update your Lavender, but I'm not sure if you've made custom changes to it. So you'd have issues with that.
Give your custom page a class name of "hiddenpage", then add this to your customise ACP
display: none !important;
This will stop that invisible blue box appearing next to your users icon.