Every-time you finish your highest floor you need to RuneScape gold reset. "Do I do the lowest floor for every course?" I don't have any clue what you mean by this question. Rushing generally gets more xp but performing all rooms can be more relaxing. That is a personal choice. You receive xp bonuses for the number of monsters you kill and the rooms you enter. The amount for entering rooms is greater than that for killing monsters so constantly enter every area but just kill creatures if you want/need to. That's personal question. What do you enjoy doing more? Training in one place or dunging to train many things?
Fractite is the dung equivalent of rune you are able to use it at level 40. Depends on training methods. If doing them with a manual you could probably finish almost all of them in a single moment. I would hazard a guess at about 10 hours play time to get everything except that the three you mentioned. Depends on which you anticipate doing. A greater strength is typically used for people that pk/duel. Mage and range may be the same level it will not impact your combat level unless one overtakes your melee battle. Normal - oak - willows is generally the arrangement for coaching woodcutting. I would sell oaks however willows I'd burn for firemaking.
Do you want prayer or straight atk/str/def levels? Which ought to decide for you. I personally would favor with more prayer so I would head to mountain giants. After the 40s I would say mountain giants to get additional prayer and flesh crawlers as already mentioned. Things won't change much until the fifties when moss giants may be an alternative to mountain giants. When you reach the sixties you can even consider stronghold of security spiders.
Okay, so I want most of the fundamentals, I'll post what equipment I think and if you could edit it it'd be good, and also tell me the approach, I have a vague notion but experience would help. I have 87 Magic, 80 Defense and 83 Hitpoints, if those stats are not enough I'd probably train them so allow me to know. Additionally, I am aware soloing rex may entail killing prime and ultimate, therefore for reference my scope level is 79 (80 easily), and 82 Attack and Power. I am mostly doing this for money, so if rex really isn't decent money anymore/ever that will be great to know as well. Thanks.
Should you apply the Burstinglobs buddies chat, there is always someone who is hybridding and needs a solo mage partner to kill Rex about them whilst they kill Supreme and Prime. This means you don't need to worry about Supreme or Prime whilst you're down there, unless either of you are bad at what you are doing. I'd take Tubby's set up with mystic boots along with buy OSRS gold a Ring of Life until you're confident, then it is possible to start risking a little more expensive gear.