Champion Noobproving

Edit - Sorry for the bad title. totally my bad.

(By "noobproving", I mean NOT "proving that someone is a noob", but "making noob-ness less impactful" or "preventing noobs from performing poorly from their lack of some sort of non-interactive playing skill". or a design called fool-proof .)

TL;DR - I suggest 2 QoL changes here. They won't be direct buffs.

Hello fellow summoners and possibly Rioters.

I'm not really skilled, so I would make some mistakes, especially if it comes to game balance. But I still think I can put my idea about reducing game difficulty without reducing interactive gameplay. I list up some of what newbies/unskilled players would do in mistake and how they can be prevented. I don't mean actual buff/nerf here.

1. Wasting mana on Frost Shot

I sometimes make mistakes that, using her Q on minions, and keeping it on when hitting a champion with enough AS. They are small mistakes that costs only 8 mana per wasted shot, but it can be prevented by a rework. Some other champions might or not suffer this sort of small problems.
Solutions I can think are:

• Cost mana over the slow's duration which only refreshes on hitting/shooting, so she can rapid-fire at one champion without mashing Q. This actually halves Mana Charge's (Tear of the Goddess) mana cost and boosts its charging speed a bit. I'm not sure whether or not this might be a massive buff.
• Change it from an on-hit to on-attack (similar to Vayne's Q and W) and make it only trigger when hitting a champion. It would help her if she fail to turn it off when shooting minions. This can be a small nerf since it won't be able to slow minions/monsters or be combined with Runaan's.

2. Standing too close when Laying Waste and Missing Starcall

Some champions have auto-quickest cast and auto-target spells like their Q's, which don't have quick-cast range-indicators. I use the range-indicator for every champion's every spell, as it helps my aim, but some spells don't allow this by design. Some are spamming spells (e.g. Karthus, Cassiopeia, Urgot), some are reflex-based spells rather than well-aimed ones (Fizz, Riven's E), and some are auto-target (Soraka's Q, Sona's non-ultimate probably including her new E). Some players fail simply because they don't know how far those spells can hit.
Solutions I can think are:

• Have range indicators for those spells. This should be an option, as they are originally done by design for reasons.
• Allow players to choose whether or not to have an indicator for each spell. For example, indicator-quick cast for Zilean's Q and E, while non-indicator cast for R. Non-indicator for Morgana's E, indicator for Q, W, and R if possible.

Sorry for the huge wall of text, and probably bad English (not my first language). Thanks for reading!

I would like to hear your thoughts.