I think your points are going to run into problems with property ownership and public space expectations. If you take your clothes off in the middle of a public park, you have no expectation of a right of privacy. If you do so in a bathroom in your house, you do. It can get trickier on someone else's property, but I suspect the law has stabilized expectations in that arena as well, i.e. you can expect privacy in a bathroom, but not on the main floor of a business. Employers have certain rights and restrictions as well because employment is voluntary, just as is entering a business. I also very much suspect that it takes more than a very bad video to get someone convicted.
1. I think here we're really talking about warrants. The police still need to produce a warrant to request video from a private owner, and that should extend to usage of public/gov't-owned video. If they "take" the video from it's source without a warrant, that should be thrown out in a court of law. The police operate under rules governing the proper collection of evidence for use in a court case. We just need to make sure those laws properly apply to the usage of video, just like with any other source of information.
2. Unfortunately you are making a Luddite argument here. It would be like basing an argument in 1908 because cars could go 10 miles an hour. The one constant with technology that's of great use is that it improves. The quality of cameras, available data storage, etc. are only going to increase and improve. So this is an issue that will go away. It only applies to the past, not to the future.
3. This is essentially the argument that because we don't have perfect enforcement, we should get rid of all laws. Humans are inherently flawed, this is going to be a given in any system involving human beings. There fore the real question is, what system minimizes that, not whether it will occur or not.
4. It's getting better every day, and again, the system is designed to minimize convictions on poor evidence, such as grainy videos. If you can make this point, a defense lawyer can probably do so even better to a jury.
5. This system already exists via paper, making it electronic just makes it more efficient. The proper response is to make sure that laws are properly rewritten to make sure that new ways of collecting evidence still have to comply with existing processes. It's up to our governments to revise the body of law so that holes are sealed up.
The correct non-luddite response to new technologies is not to ban them because bad people misuse them, it's to ensure that the existing expectations of proper behavior are properly codified.
And as for the new boyfriend, dads should have a 100% ability to review every part of a young man's life that wants to date their daughter. Dads are men, we know exactly what's going on in your disgusting perverted head, and if you try that with our daughter, not ending up dead after we get through with you is a good outcome for you. Definitely there should be broken limbs, gelding, and branding in obvious spots so its easier for the next dad to clear you off with a shotgun and to prevent any repeated bad behavior. : )