Safer to lift before or after kickboxing?

It depends on your body's reaction to it. If like you say you feel fine, then it should be okay. I wouldn't expect to be breaking strength records with that arrangement but if it makes you stronger for your sport, then go with it. I would be mindful that your soft tissues (especially the connective elements like ligaments and tendons) will still be fatigued from your early morning session, and that you risk an elevated risk of injury in your evening session (both acute injury from not being completely rested, and chronic due to interfering with the repair process). You will not be 100% fresh despite feeling it.

 

There is a guy who is an expert in lifting and a former kickboxing world champion: Jim Graden of Seminole, FL. You may want to look him up on Facebook and ask him for advice. He is a former Joe Lewis student and knows a lot about both.

 

I found a good middle path was to follow Pavel's pttp in the morning (only 12-20 reps in total with and going nowhere near failure) and train in the evening.

I have never found it possible to follow any other strength training program while doing another sport, unless it's just 1 or 2 maintenance sessions a week.

 

Me too.

Heavy weight training, particularly training to failure, seems nigh on impossible to combine with doing another sport seriously.

I’m sure professional athletes can manage, but they have time to recover whilst I have to go to work.

 

Most Sports have an off season where the gains are made and an in season where volume is managed to ensure strength isn't lost even that's hard, most athletes lose size and strength in season.

Martial arts are year round with no off season, strength gains can be made but there isn't a one size fits all method as volume and recovery is highly individual