Maybe a bit U.
I would absolutely not be difficult for the sake of it as that is just being an arse (and I am a tenant) Different if you have illness or similar and have more to juggle, but the LL and agent might be perfectly reasonable. You will have an inkling of that by now as you know them.
First you need to know whether you need a landlords reference or not. If you don't, you have more discretion as to what to allow/ negoitiate.
I agree that suggesting open day/ a day/ time of the week that might suit for viewings. Or a block of days, and get this agreed in principle before you consent to anything.
Photo-wise, you could say photos of kitchen, bathroom, garden only perhaps, so wouldn't be as intrusive. Most agent do floorplans nowadays so it would still give buyers somethign to go on.
Allowing some repairs is one thing, but upgrades are something different, and you need to know how much disruption they would cause.
Equally it will probably be easier (and maybe therefore cheaper) for the trades involved to work in an empty house so shoe horning 'repairs' in now, might not be the best idea anyway.
Give and take is required and hope you don't have a bad experience with LL and agent again. I know how this is as we had previous LLs insist on viewing when DH had just come out of hospital AND they had given us shock news that they were selling up. We coudln't say no as we 100% needed the reference :(
Lovely to hear so many nice LLs on this thread :) :) :) We have a lovely LL now, but have had many real shockers!!!