ColonelPogs

If you want the wall wall mount form factor, but for cheaps CPC have something for you. https://cpc.farnell.com/pro-signal/psg3394/24w-wall-plate-audio-amplifier/dp/AV29005

I my experience, with young people and old DSLRs, most of them have a minor brain implosion when you explain you have to use the viewfinder and not the screen. One thing to consider, it's not just the faff involved with operating the camera. There's also the issue of getting photos off, which if it's too tricky will end up being your job.

I've seen some theatres who have converted older Beta Pack style dimmers (pre DMX dimmers are now basically worthless) into hot power distros. In this situation you could even retain the fuse holders or breakers. One thing to bare in mind if you're getting power put in for LED lighting, is a lot of LED lighting has a very high inrush current when first switched on. So any isolators being put in should be overspeced, and type C MCBs should be used.

There a loads of either 'Architectural DMX controllers' that will do what you want. But are probably a bit expensive, I've used one made by Nicolaudie. You program it with a laptop in then works as a stand alone all controller. I used one in a venue, and it has basically just sat there and worked for about 10 years. The alternative is a DMX replay unit, these are a fairly similar, but you need to use a lighting desk to program them. They have a DMX input and will basically capture and store the DMX signal sent by the desk. The other piece of the puzzle is a DMX merger, this is a handy bit of kit that will take two DMX inputs and let one take priority over the other. So you handy controller will do it's thing, and then your lighting desk will take over without any intervention.

Another thing to bare in mind with placement is the higher frequencies are more directional. So you will get a lot of the bass and low mids coming out in all directions, but the higher frenquencies where a lot of the detail in the vocal is sensitive to direction. That's why most speakers have the hight freqency drivers at the top. As @SamanthaDhas advised getting the speakers high and tilted slightly down is best. But if you're able to get music loud enough, but not vocals from the mic I think the issues might be further down the signal chain.

Erm, I'll be honest, when I see Vonyx kit my heart sinks!! I've had a look through the manual, and there isn't really much technical information. Adding an additional may help the situation, but on the other hand it may not. The inputs are intended for mics, so it should be fine without. But it doesn't actually state how much gain it's added to the signal. I would advise hiring a mixer (or even better borrowing one) and trying before you commit to buying anything. The other thing that may be worth trying is borrowing a radio mic, these basically output at a higher level. If you're buying a radio mic, avoid anything that uses the 2.4ghz frequency. It's the same band as wifi and bluetooth, and they have a habit of working great in rehearsal and then falling over when an audience (and all their devices) turn up. Another thing is which input are you using, if you're using the jack (Mc2) and the output on the mic is an XLR then you may have more luck getting an XLR to XLR cable. If you give us an idea where in the country you are, someone may be able to recommend a PA hire who can supply some kit to test with.

Most mixers should have mic preamps built in, it's more a case of using the correct input and making the correct adjustments. Even something like this should do the job without extra preamps. https://www.thomann.co.uk/behringer_xenyx_802s.htm this has up to 60db should should be plenty gain for something like a SM58, or for announcements even a cheapy dynamic mic will do. Make sure who ever is doing the commentary understands they have to talk into the mic, not whisper vaguely in it's direction.

Are you plugging the mic straight into the PA, or are you using a mixing desk? If the music is loud enough, but the vocals are too low it sounds like you need to gain up mic signal. If you post up a picture of the kit I can probably make some suggestions.

https://stagetimer.io/ It's intended for speaches/seminars, but would probably do the trick.

I used to work in in Grammer school. On whole the students were fine. However a significant proportion of the teachers were absolute primadonnas.

As above you've not really given us much to go on. Also what sort of speakers are you planing to use it with? If it needs to be battery powered I expect Coomber will do something suitable. But like all their stuff it will look like a bloke called Derek made it in his shed.