As someone who has an *AMP setup on a personal device, I would say (anecdotally) I have never experienced any ill-effects from leaving it running continuously.
Will it conflict with any network-related apps (Tor, Torrent, ...)?
Anything that takes up a port can potentially interfere with another application.
Regarding specific applications, definitely not for Tor or torrents, at least in most instances. Skype can be one potential conflict to watch out for since it uses ports 80 and 443. Short of that, perhaps programs that run on ports 8008 or 8080 (assuming you even have your development setup set to run on those ports). Otherwise, there is likely little to be concerned about here.
Would it have some impact on the performance when for instance rendering a video or playing games?
MySQL can arguably be resource-heavy in terms of memory usage (several hundred megabytes or more), but whether that actually makes a difference (especially when it's inactive) would be something you would have to judge yourself. Apache requires almost nothing to run. Again, personal experience, I have never had to turn off these service to get good performance from games/rendering/etc.
Does it have noticeable impact on battery, when not using an adapter?
Not that I have ever noticed.
Any security concerns?
I would say no more that running it in the first place. Public wifi might be a small danger (since running any kind of service can present more attack vectors) but my guess is that danger is relatively low.
Why do you believe it would cause problems? – JakeGould – 2018-04-14T02:31:06.717
I don't know, that's why I'm asking – matronator – 2018-04-14T03:35:24.947