Ah, and you find the key flaw with fire- devils.
The only answer I have is 'try with the flash infusion', sicken with smoke storm, aim to dispel their spells with unraveling infusion, prevent invisibility with foxfire (as faerie fire).... or try to demoralize your opponents by curing up in a corner and crying.
...yeah. Pyros can't do much when devils show up. A water kinectist has it better- they can pick a physical blast to just smack things around before you go with ice. Might hurt an image early on, but it works.
Lemures might be the worst of them all- they show up at early levels where you don't have room for wild talents that give you at least some use in the fight. It honestly makes me wish fire had an 'explosion' blast or something.
I guess you could also try a kinetic knight and play something that is enough of a martial that it could just use a sword. That works. Then you can just use a fire sword later.
I wonder if you could try a trip attack with a kinetic whip? But yeah, lemeres covers it pretty well. If the devils arrive before you have any such option you're reduced to aid anothers, or unimpressive attacks with some backup weapon.
Interesting solution I found looking at the ooze guide- have a level 16 alchemist friend infect the enemy with a tears of burning flame. It is a weird symbiote ooze. As the name implies- it is a fire creature. It forces the infected creature to gain the fire subtype.
Although the subtype might be part of a buff given to willing hosts (unwilling hosts just get debuffs). But maybe someone can do a bluff check?
"oh no, the ooze got loose! We have to catch it before he grabs and uses it"- Briar rabbit the alchemist.
The new stuff which fire can use is specifically melee. So, no.
I feel like the identity of fire as a kineticist element is largely defined that your excellent damage potential, area of effect, and debuffing ability is counterbalanced by your lack of non-combat utility and the relative frequency of enemies being immune to fire.
In a lot of ways it's the photonegative of aether: which is weak in damage, AoE, and debuffing but excels at utility and can bypass the most kinds of resistance (the double aether blast is force, which nothing resists).