F2P: merge vs inherite

Uh, how can anyone possibly answer this without know WHAT units you're talking about?

It depends on who you are talking about, there are character who have skills that are so useful that is better foddering them off than merging copies, examples of these skills are DC and wrath. If those 5* characters have skills that also 4* heroes have then it isn't that worth foddering them off. At the end merges can help sometimes but not that much, the only reason i would merge instead of foddering them off is because that character is in my arena core and my objective is staying in tier 20. Also if you don't use that character very much then keep a copy and fodder the others, in my case i have 4 Sanaki at the moment and I intend to use 3 of them as TA fodder

I struggle with this too. I am safely tier 18-19 without any merges on my arena team. I decided to merge arya and deirdre after the first legendary banner now i just pulled a bike from hero fest and i think I might kill him for my Nowi.

I'm also f2p and i merge characters like reinhardt and nowi.
They are easy to get (can be 4*) and have nothing special to inherit to others. Since we are getting more feathers than i can use i'm spending them upgrating to 5* these kinds of characters and merging them,

Depens on your goals. If you want a variety of strong characters, inherit. If you want a chance to consistently play tier 20 arena, you HAVE to choose a few units and invest a lot of feathers to merge them to stay at least competitive

It depends on the character's skills and rarity.
If we are talking about a character with a lot of potential for merging like Nino, the best thing to do is merge her, but if you want to give her Groonblade+ to another unit, you should go for that if it has bad IVs/you already have one with decent merge

Personally I always keep my 5* and merge, I never sacrifice them. I just can't bring myself to lol. I'm also f2p.