^ My opinion on smoking/snorting is that it depends on the form of heroin which is ideal, regardless of experience, you are better off smoking black tar or base heroin and better off snorting #4 heroin hydrochloride. This is because smoking #4 is a waste, unless you cut it with a specific ratio of caffeine (which is impossible to determine since you wont know how pure your heroin is) and snorting base or BTH is impractical.
With that said, I think that smoking is probably a slightly safer route of administration (ROA) for a newbie, this is because it is much harder to take in a large dose at once, also, the effects of smoking hit faster than the effects of snorting, which means a novice user is likely to be overwhelmed by the effects of the drug before they can ingest a lethal dose. Please do not misinterpret this comment as me saying it is not possible to overdose by smoking heroin, as this is still definitely possible.
I prefer snorting heroin to smoking it, I find the slower onset of the high enjoyable (I like to slowly titrate my dose upwards when I snort heroin) and I generally feel I get more out of my dope when I snort it. At this point I should indicate that where I live the primary form of heroin available is #4, to my knowledge I have never used any other type of heroin, if another form of heroin was the predominant one available to me it is very likely that my preference on ROA would be quite different.
If you opt to snort the drug, start very small, I would stick with the 10-15mg that I advised in my last post and wait about half an hour before using any more. I find it more effective to split the dose I am snorting into two very small lines or bumps and snort one up each nostril. You should be aware that heroin has a low oral bioavailability, this means that ideally you want to avoid getting much of a drip at all. The drip is essentially the drug exiting out the back of your nasal passage un absorbed and all of this will be swallowed and hence taken orally, with a drug like methamphetamine which has a good oral bioavailability as well this may be less of a concern, but when I am snorting heroin I am careful to inhale it rather lightly.
In relation to nodding off and falling asleep worrying me, generally it doesn't, I use opioids like heroin infrequently and on the occasions that I do use them I do so with nodding out as the end goal. I enjoy the whole spectrum of heroin's effects, that is why I like to snort small doses of heroin over a longer period of time, until I am eventually nodding, this way I feel like instead of going straight to nodding I get to enjoy all the pleasant levels along the way but still eventually nod out.
I don't think nodding is inherently dangerous, especially if one is careful to slowly titrate their dose upward as I generally do. Obviously it takes a higher dose of heroin to be nodding than it does to have a moderate buzz, so in this sense I suppose it is more dangerous than looking for a milder effect, but so long as you aren't using other drugs with your heroin, I think you can get a nod on and not be dangerously close to overdosing.
I know you directed the last question at frosty, but the reason it is important not to do it alone is that if anything goes wrong you are very unlikely to be in a position to call emergency services for yourself. If you have someone to look after you while you use it, they can put you in the recovery position and call an ambulance for you. If Narcan is available to you then the person supervising could administer this which should (at least temporarily) reverse the effects of heroin. Ideally this will not be necessary, but it is much safer to have somebody there just in case than it is to go at it alone.