Home security questions can anyone help?

I don’t want to call and ask some company that’s gonna bug me later if I decide to not buy.

First of all we have two dogs a Rott and German Shepherd, we also have guns in our room. However, dogs are crated at night. We also have two toddlers that try to open doors and get into everything. Someone knocked on the door recently and my dogs didn’t even hear them.

My husband thinks we don’t need a system and we can just install motion sensor lights outside.

We also have terrible internet connection! It goes in and out multiple times a day.

Power outages are also somewhat common with bad storms in our area. Our house is in town.

We have 4 windows in front of the house that are accessible from the ground, but the windows on the back of the house you would need a small ladder. We also have 3 doors to the outside.

Do you have to have a good WiFi connection?

How do security systems work with power outages?

Are 100lb+ dogs too big for motion sensors in the house? I read there is a weight limit and could trigger the sensor.

Are motion sensors really necessary in the home?

What is the cheapest but most reliable system?

What do you guys think? Is my husband right just install motion lights outside? Lol