Re: The way others see you
That's a very widespread problem you describe.. the whole 'am I ready' thing. The bad news is.. it probably won't go away until your are so far into the yudansha grades that somebody else will make the decision for you. The good news is it is a great way to learn something about yourself.
Every grading is a big step in it's own way. And I for one prefer by far to be 'more than ready' when grading. On the other hand there is always more one could have done. If you have the patience then wait half a year and gather more trainings under your belt before taking the test... if you feel the desire to test now, you might want to ask you sensei or a senior student.
In my dojo I encourage my students to grade when I think they are ready. However as they rise in the system I will try to leave it more and more up to them to decide. One reason is that the first grades are not about technique as much as just for 'getting your feet wet' when it comes to grading (in my opinion). Later on however the difference in progress of each student will be ever growing depending on talent, injuries, time to spend in the dojo just to mention af few factors.
In the end - if you can get to the place where you can decide based on your gut - feeling then you have reached a new level in your Aikido. What we practice is very much about being in touch with our own emotions, accept them and handle them (as our ukes) with compassion and understanding.
You mention yourself that you are not in this for the belts but for the practice and the good times - If you can accept this and act upon it you will start enjoying your practice even more, but it's not easy. Most of us have ego's of a considerable size and those pesky things will stick there heads out on the odd (and even) occasion to mess up your personal balance. Accept them and welcome it as yet another chance to grow and become a better person.
In the long run the distance from beginner to perfection (I use thise term as a provocation) is just as long for those who grade 'on time' according to the schedule as it is for those who take the somewhat longer road... Those grades that we use for inspiration and a slight sense of order in the chaotic mass of aikido techniques are great tools, but don't let them blur your view of the real purpose.
I am babbling here. hope some of it makes sense. Just want to finish by telling you that I have seen people train for decades staying at maybe shodan level or even kyu-level, and I have seen people sprint through the kyu grades based on prior experience, talent or even political reasons. Sometimes it is just neccesary to get some new students to a black belt level (formally) when a new organization is being created f.ex. However I have met 1., 2. and 3. dan instructors that inspire me a far bit more than some with a 5. or 6. dan.. it all depends.. on me.. on them.. on the whole system. In the end we are just praticioners of the same art, and it is what we do on the mat that is important.
Just as you can enjoy the great music no matter what 'belt' he or she has on his instrument. If you are an artist formal testing is a great way to focus your progres, but passing the grade is not the goal. Formal grading is - as far as I think - a tool. Not a goal.
Now try to let it go - meditate or do rigours workout or whatever help you center yourself - then go practice and have fun. And grade when you feel that it is the right occasion - for all the reasons you can think of. Don't overthink it - just feel it.