Not worth risking it with Cuban immigration - it can be a hairy experience at the best of times.
Can't say I've ever found it a hairy experience - grumpy and unsmiling staff, boring and time consuming for those of us in the queue, yes, but hairy in the sense of scary or intimidating? Never! As long as your documentation is all in order, that is, your visa and import/export forms are filled in correctly, you have your return air ticket (rather than an open ticket), your passport is in good condition and all available for them to examine then it's no worse than most other non EU immigration set-ups and certainly better than some.
As for the 'camo' gear, yes, leave it at home. Military matters are taken seriously in Cuba and that includes uniforms etc but it will also not only make you stand out as a tourist even more than usual but also mark you down as a bit of a freak as far as the locals are concerned! The fashion for wearing military style gear is not understood by Cubans who go out of their way to try and customise their clothing and be different from each other. 'Why one earth would anyone who doesn't have to wear a uniform actually choose to wear one?' seems to be their attitude. But then again, they seem to regard most male tourists as being scruffy dressers anyway! 'Dressing down' is not a Cuban concept if you can afford not to - I can remember being asked why so many British men on holiday in Cuba dressed like farm or manual workers when they clearly had to be in much better paid work or how else could they afford to holiday in Cuba in the first place?
For the same reason they don't get 'combats' either - why load yourself down with all your stuff in pockets if you can afford a bag to carry it round in? One of the most popular gifts I once took was the lightweight, giveaway conference brief cases leftover from one that I organise. Any academic here accumulates laods of them and thinks nothing of it. It made me realise what a throwaway society we are - here they would have ended up being thrown away with the rubbish after the conference was over if I hadn't rescued them - there I was being proudly shown them in use on my trip the following year.
SM