There’s a lot more to improve.
Here’s my take for a small/light - space launch vehicle inspired by JAXA’s SS 520-5 but mine is just slightly taller and can carry 20kg to low earth orbit (RSS). Utelizing a 3 stage design with the first 2 stages running pure solid fuel, unlike the SS 520-5 that launches on a tilted tower, I made mine a little different and uses active motor guidance for launching it inspired by the Onyx missile system to give the rocket a desirable pitch since solid motors can’t be vectored for directional/pitch control.
I made a few changes since my last post “Cool but impractical”. I removed the spin on launch and the rocket had become slightly more taller and heavier. I then added a simple vizzy script for auto orbit which takes care of every stages. The script gets you to orbit safely with 4-5% remaining liquid fuel to do orbital adjustment at least would give you a circularized 400-600km orbit adjustmemt. Also to mention, due to the nature of being a small rocket it has insane TWR and accelerates like crazy! So just to lessen the impact on precious satellite payloads, I added some shock absorbers.
I made a short video demonstration. I call this rocket “Maya” SS/CS LV (Small sat / Cube sat Launch Vehicle) - Maya is a filipino term for the bird Sparrow.