My own altar is refreshed on each of the sabbats and starts each period as an offering to the Gods with a nod to the energies of the elements. As the period between sabbats progresses it becomes increasingly more cluttered with spell workings, new offerings and general magical paraphanelia so by the time I am ready to change it, it has become a complete hodge podge of a working altar and well in need of a refresh.
In terms of disrespect, like I say, a lot depends on personal viewpoint. Many witches consecrate their tools and some (particularly Wiccans) will dedicate their tools to the God and Goddess. These witches are unlikely to want anybody touching these items as they have been assigned a sacred purpose. Other items are used to direct the energies of the witch and being touched by pther people can have a negative effect on the energy link between witch and tool. You’ll find this particularly with tools used for casting circles (wands, staves, athames) and particularly with Tarot cards.
To me, the intention of why a person is touching my things matters. If I am doing circle work with another witch, I’m pretty laid back about him/her touching my things. I’m also ok with children and animals as I don’t expect them to understand the meaning behind my altar so I don’t consider it disrespectful that they want to handle my pretty things. My cats regularly trog over my altar, the odd tarantula has had a wander on it once or twice and my degus have chewed several precious belongings over the years… I’d be annoyed if an adult picked my things up without asking and I’d be hopping mad if another witch or someone who claims knowledge of the craft did because I would expect a much greater awareness of witchy etiquette from them.
Some witches don’t mind at all, they work on the basis that any energy is good and believe their tools to absorb the energies of all those who handle them. Fair enough if it works for them but I’m keen on good old fashioned manners and I think it’s a bit rude to handle the private belongings of another person without their permission. The exception for me would be if another witch put their things in my personal space. Leave a wand on my sofa and I’m going to move it. Environment is important to a witch and anything in his/her personal environment becomes fair game.