Okay, so this may seem off, but I've been searching everywhere and I am unable to find the answer I'm looking for.
When you craft a 3* item, is that item weaker if you do not max the 2* item first?
Same with 4* recipes, I know they require a 3* to be lvl5+, but if you craft it immediately at lvl5 (rather than maxing it at 10) does the new 4* item have less stats, than if you were to max the previous item?
No. The heat level of the precursor item does not matter (as long as it reaches the minimum required to upgrade it).