Home network reorganization - is the next solution reasonable?

Question

Computer networks

My parents in the house encountered such a network organization:
The network comes from the provider via optics, then from the converter it goes to the first router with the NETIS WF 2780 AP. From it it is distributed to some users by wire, incl. through two D-LINK DES-1008C switches, and over the air.
It also goes to the second router (the same model) to another floor, from it to several consumers directly and over the air.
Total for a pair of wireless networks (2.4 and 5GHz) on each of the two floors, no signal outside the house on the site.
Some cables are poorly crimped, some are crookedly embroidered in sockets (well, I did it myself, you don’t need a lot of mind here, just a tester cable and a crimp).
It is assumed 12-15 consumers by wire and an indefinite number by air. Among consumers there are potentially sensitive to speed - NAS, media players, work PCs.
I don’t understand networks, but it seems to me that you can do better than what has been done.
There is an idea to put a normal router at the entrance, connect an access point to each of the two floors, and one / two APs to the local area.
I want to make the wireless network seamless.
I would also like to be able to connect to the network remotely via VPN.

schematically

То, что сейчас
То, что хотелось бы

Based on this, the questions are:
1. Is the input-router(s)-AP circuit normal?
2. The equipment is supposed to be Mikrotik. What to look for in order to serve ~15 consumers (most of them are non-permanent) over the wire, including 3-4 access points?
In my lamer's opinion, something like this:
- Router: CRS125-24G-1S-IN
- Internal AP: MikroTik wAP ac ( RBwAPG-5HacT2HnD ), one for each of the two floors
- External AP: MikroTik OmniTIK 5 ac ( RBOmniTikG -5HacD )
3. Where to look at the settings to do the following (translation: poke your nose at a good site where everything is written for lamers, such as NAS4free is written by 2gusia aka mikemac):
3.1. Seamless Wi-Fi network through CAPSMAN
3.2. VPN? It is necessary to make it so that you can remotely connect to the
3.3 network. It is desirable to bypass locks on the router
3.4. DynDNS or equivalent, preferably free, and without bread (c)
3.5. Competent organization of security
4. Will it be necessary to somehow interact with the provider when changing equipment? I have 2kom at home, it comes over a twisted pair cable, if I need to change the router, I either need to replace the MAC of the new one with one similar to the old one, or go into the provider's personal account and prescribe a new MAC there. I have not met with optical providers before - is it the same there, or do you need to know some logins and passwords?
Thank you in advance!
PS I ask you not to campaign for Ubiquiti.

Answer 1

I don’t understand networks, but it seems to me that you can do better than what has been done.
There is an idea to put a normal router at the entrance, connect an access point to each of the two floors, and one / two APs to the local area.
I want to make the wireless network seamless.
I would also like to be able to connect to the network remotely via VPN.
The idea is right and true. The diagram is also correct.
At the expense of equipment, instead of an expensive router, I would put ubiquiti edge lite (such for 10-30 people is quite pulling, like an office option, the settings are convenient), and plug it into the dlink DGS 1100-24 switch, where I would plug everything else ( consumers and access points).
And yes, Apple Airport Express hotspots are great for hotspots! Set the same password and network name at all points, yes, under Windows they work fine and are configured.