Hi, I ride dailly about 25 miles to get rid of "the love handles" and apart from that I really enjoy biking getting a breath of air after work. I am getting much more serious about it after a month or two daily rides. When buying the bike (Trek Soho 2) I was advised to bring up the saddle to a height that did not feel comfortable. I lowered the saddle a bit and after riding for a few weeks and getting used to the saddle,
I repositioned the saddle upwards. When riding, I can now stretch my legs completely when leaning on the heels of my shoes. Will that be OK? Or should it even be a touch higher?

That's OK and it's at the bottom of the range for most efficient cycling. Typically this range starts with your heel on the pedal and legs straight (without rocking sideways) up to about 7-10mm above. The higher position tends to help faster spins and are used by track-racers. For most people, the heel on the pedal will be fine. Too low is more problematic than too high because it hinders spinning, promotes mashing and causes knee issues.