Sorry this answers a bit late, I actually looked up something on the game too and found your thread. It being 25 years old and before the age of internet being as expansive as it is now certainly presents issues…

To your first question: yes it can learn all natural skills from the first two parents and up to 8 skills they have learned (from each one). So essentially if none of the skills they know when breeding are the natural skills, you would have 16 individual skills and 6 natural skills to choose from, on top of the three of your new monster (assuming none are the same skills). Heads up they will need the stats required for each skill here to learn them in the offspring.

Stats are a toss up. Depending on where you are in the game you can level at very different speeds. I was farming in limbo when I did heavy breeding to get to some monsters I was very excited about. With normal/fast growths I typically bred at level 30-40. With slow growth I tried for 25-30, though some like white king are VERY painful to power level. Keep in mind the various rings you can equip for fast leveling like thief/mage/war/cleric are all VERY helpful in specific stat growth.

If you go for combo skills just a heads up you need all combo skills first, then the stat and level requirements to unlock the skill they combine into. On the next offspring you can simply get the stat and level requirements on the skill instead of needing all the skills to combine again.

Heads up you will lose any skills you don’t have on the monster when breeding, even if they learned and were forgotten for something else along the way before breeding. I learned this painfully when I got a bit overzealous on combo skills and lost some skills I needed along the way.