Gravel tyres on cyclocross bike. Size, tubes, design, speed!

[Duke Caboom]

Non expert here.

I race duathlons on hard packed forest tracks using a cyclocross bike with 33mm cyclocross tyres on Mavic a317 wheels.

Last week a last minute puncture meant using my ancient mountain bike. There was no wind, which helped, but there MTB was barely any slower, much more comfortable and better when I needed to use less tightly packed parts of the course.

So I want to get the best of both worlds by fitting wider tyres to the cyclocross bike.

At the nearest point, just behind the crank, I have 52mm width. I don't ride on thick mud.

Will 47mm tyres be ok?
The gravel drains quickly and it's a very dry part of the country so will speed-focused tyres, with a central slick be ok?
With these tyres offer enough protection to not need slime filled tubes?

Thanks