I beleive, all this extra steps worth not much compared to (re)installation from scratch ?
An installation from scratch means a new, empty database. All products, all product pictures, all customers, all orders gone. If you can afford this, sure, go ahead.
Doing a fresh installation, then pulling over the data is probably possible, but much more complex than the recommended upgrade process. If you want to try: backup the database in the old shop and keep that old shop running. Then restore that database in the new shop. Then copy over all files in img/, upload/ and download/. Then run the upgrade SQL query. Then cross fingers I didn't forget something in this list. It's asking for trouble.