Simple - not complicated
Simplistic - overly simple for the situation under discussion
toe: as in “toe the line” (metaphor from -probably - military usage): accept/follow a policy, guideline or instruction from higher authority (even - especially? - reluctantly)
tow: pull along (or, more rarely, the colour of broken flax or hemp fibres, hence a metaphor for a colour and/or untidiness of hair, cf. Boris Johnson)
Is it really about untidiness of hair or just the color? Relative to both these words, ‘tow head’ is used to describe flaxen haired people in some places. Those unfamiliar with the term may mistakenly interpret it when spoken as ‘toe head’, invoking humorous notions of what it means. Sometimes those notions seem apt as in the case of Boris Johnson.
Yes, I’m more familiar with the “colour” idea, but a couple of dictionaries online also refer to the “untidy” sense as well.
tact - sensitivity, diplomacy
tack - (among other meanings) the direction of a sailing ship
Thus, if you change your approach to something, you *try another tack."
inclination: a tendency
inkling: a hint or suspicion
I have an inkling that people who have an inclination to confuse words are not reading this thread.
IOW, they decline to read it. 
I can’t comment on how the terms are used today, but I’m convinced that, originally, whether one was described as “tow-headed” or “flaxen-haired” depended on the texture of the hair.
I saw a demonstration of an antique flax threshing machine once, and was impressed by how the flax fibres were soft, silky, and flowed exactly like the sort of hair you don’t often see outside of shampoo ads. The tow – the coarse outer husk of the stalks – was dry-looking and curled untidily.
Interesting. The only people I recall being called tow-haired had very light skin and very light almost white hair. They were all boys and young men. I think women tend to be called flaxen-haired. I never picked up the sense of untidiness before but I sort of have an image of all of them with obvious cowlicks.
I’ve mostly heard tow-headed applied to children whose family had a long history of being blonde as children but having darker hair as an adult.
Axel: turning jump skating figure
axle: pin or spindle on which a wheel revolves
I have always thought of inflammable to mean highly flammable.
Same here, it seems to be a trait in the boys of my family, and they are always called tow headed.
For starters, there is the term ‘pyrophoric’ for substances that ignite spontaneously:
The dictionary says flammable = inflammable and flammability = inflammability, so if you need subtle distinctions it seems you should be specific.
We have correct usage and common usage, they are not always the same. I was simply offering the way I used the word hoping others would do the same. Maybe I should have specified that.
I have an inclination to go sledding down?
And so far as I’m concerned an inkling is a baby squid, and nothing you can say will convince me otherwise.
That’s a dubious distinction, but what we certainly do not get to do is individually pick our own meanings for words.
(Except inkling, I’m firm on that.)
Kinda like this?
“When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.’
’The question is,’ said Alice, ‘whether you can make words mean so many different things.’
’The question is,’ said Humpty Dumpty, ‘which is to be master — that’s all.”
― Lewis Carroll, Through the Looking Glass
IMO/IME/AFAIK “flammable” and “inflammable” are precisely utterly identical in meaning. There are zero nuances here.
Because “flammable” was coined by the US safety industry after they realized that warning signs reading “inflammable” were being misread by morons as meaning non-flammable. So they needed an unmistakable term meaning “able to catch fire”, just exactly the same as “inflammable” actually means. So now by law the warning signs in the USA read “flammable” - a word made up by the US regulatory apparatus.
Although I am now totally on board with “inkling”. Great coinage there @Riemann !
Out of curiosity, I Googled ‘what is a baby squid called?’. The answer is ‘squid fry’. Which sounds suspiciously like calamari.
If you’re going to eat fried squid fry, you’ll need to use tweezers for chopsticks and a magnifying glass to find them on your plate. They’re kinda small when freshly hatched.