It is both ok and necessary to stand up to doctors but it's not ok to be rude.
I ran into the situation many times where a doctor would come find me to say "I need xyz." If it was a regular resident, I would simply say "they're in the supply room on the left when you walk in" because those residents knew perfectly well where to get things. If it was a covering resident (depending on the services, we sometimes had residents rotate though for a few months at a time and sometimes just had them covering overnight for a few weeks), their ID badges usually didn't get them into the supply room so, if I wasn't busy, I'd just get the supplies for them.
Leaving the bed in the highest position and the side rails down was NOT ok and obviously a safety risk, but I'd bet that they didn't even realize they had done it. You could have pulled the doctors aside and said, "were you aware that you left the bed in the highest position with the side rails down?" Fall risk is something that nurses have at the forefront of their brain, but I doubt it's something that residents eager to place a central line are that worried about. A simple reminder "it's hospital policy to keep the bed in the lowest position and locked with at least 2 side rails up at all times to minimize the patient's risk for falls" would have probably done the trick.
The doctors not wanting to get their own supplies was probably them being lazy. I used to encounter this kind of stuff all the time when a doctor would come in the back room and yell out "Who's taking care of Suzy in Room 3B?" and we'd all just kind of look at each other and say "check the board". Inevitably, said doctor would return 4 seconds later and say "Where's Nancy?" and we'd all say "she has a phone number, it's next to her name on the board." If you enforce good behavior enough, it will eventually sink in.
I worked in a very large teaching facility where residents changed by the minute. The surgical service utilized "pre-residents" which were most often doctors trained in foreign countries who did not yet meet the qualifications to enter an official residency program. They overworked them and paid them close to nothing. Many of them came from countries where nurses were expected to just not question the doctors and women, especially, were not supposed to question men. It took a long time to train them that that attitude wasn't going to fly in the Northeast US. I did once have to speak to an Attending about a resident because he was refusing to order appropriate post-op pain medication for 2 patients. One was a patient who was less than 24 hrs post-op for a full VP Shunt replacement after removal of a calcified shunt who had required morphine, dilaudid and oxycodone overnight to keep her pain under control and he insisted that post-op shunts "never go home with anything but tylenol". This child lived far outside of the city and it was a weekend...there was no way I was going to discharge her and say "just take tylenol because I'm sure it doesn't really hurt to have your shunt just yanked out of your neck" and after several hours of requesting a script for oxy prior to discharge, I finally got one thrown at me after I went above his head and called the fellow. The other patient was a patient of the same surgeon who was 24 hrs post spinal surgery for tethered cord release. These kids tend to do really well on Toradol. For some unknown reason, this resident just refused to order Toradol saying "just give her the Valium and Oxycodone". After spending nearly 10 hrs arguing with him about it, I finally got the Toradol ordered at 6pm. I came in the next morning to find out that the child had required no additional PRN medications overnight and was doing fantastic on the Toradol. I spoke with the Attending about the situation and requested that he address it with his resident. After that, I had a much easier time getting this particular resident to order appropriate pain medication for post-op patients.
Another time I had a patient (2 month old with hydrocephalus whose EVD was clogged because of blood in her ventricles) who was exhibiting all the signs of increased ICP with a HR in the low 80s. The on-call resident (an adult resident) told me that it was "fine because she was asleep." Her baseline HR was something like 120 and she most definitely was NOT fine. Within an hour or two she went into status epilepticus and we were wheeling her crib directly into the OR.
You most definitely HAVE to stand up to doctors in certain situations, you just need to do it the right way.