R.A.D, thank you for for advices and encouragement.
When I spoke avoiding copying other's ideas, I meant making the details of guitar similar in looks and design. For an example if one would start to compare Gibson LP vs. Fender Strat he would find that there are almost no similarities at all - shape, design ,materials and hardware , even electronics and scale used - all differ so radically from each other except they are both electric guitars having body, neck, associated hardware and pickups.Same thing happens when you compare Strat to Steinberger or Parker etc.
Also interestingly many good technical or design solutions are already patented, even if not used or seen much in real production models.